flex 2.6.4 compiles fine with GCC 7 on (at least) Ubuntu 16.04 and Fedora 27.

* Revert "Travis: use --concurrency=multiprocessing only on build tests (#6872)"

This reverts commit 596d4637.

* Removing 'coverage combine' in test script

According to what was discovered in #6887, one of the problems is
calling 'coverage combine' twice without the '-a' flag. This removes
the first call within our test scripts.

Update the qt4 CoreWLAN patch to apply to macOS/OS X 10.12 and 10.13,
which both still use the CoreWLAN framework in their SDKs (although
it's apparently deprecated?!). Without this patch update, `spack
install qt@4.8.6` fails on macOS/OS X 10.12 because the linker
cannot find headers from the CoreWLAN framework.

Apple removed support for Objective-C garbage collection in binaries
in XCode 5.1, but VTK 6.1.0 and earlier set flags for garbage
collection, resulting in a compile-time bug when compiling VTK using
any recent version of XCode (i.e., Apple Clang).

This commit fixes this bug by removing the garbage collection flags
via setting the variable `VTK_REQUIRED_OBJCXX_FLAGS` to the empty
string. This variable has the same value (i.e., the empty string) in
the root-level CMakeLists.txt file for VTK 6.2.0 and later.

VTK 6.1.0 and earlier do not use paths stored in `NETCDF_CXX_ROOT` to
detect the presence of NetCDF C++ headers and libraries. Consequently,
VTK 6.1.0 does not build.

This commit fixes this bug by setting the advanced variables
`NETCDF_CXX_INCLUDE_DIR` and `NETCDF_CXX_LIBRARY` at the command line
to specify the directory containing headers and the full library path
for the NetCDF C++ bindings.

This commit removes logic from Spec that was there only to be used in
tests, and allows to set a new prefix cleanly in user's code.

The flag_handlers method was being set as a bound method, but when
reset in the package.py file it was being set as an unbound method
(all python2 issues). This gets the underlying function information,
which is the same in either case.

The bug was uncovered for parmetis in #6858. This is a partial fix.
Included are changes to the parmetis package.py file to make use of
flag_handlers.

Signed-off-by: Howard Pritchard <howardp@lanl.gov>

* Adding flags to codecov reports

* OSX builds are triggered once a day

This makes use of the new flag_handler logic from 28d8784a to set
compiler flags for ipopt by passing them as arguments to the build
system rather than injecting them into the compiler wrappers. This
avoids conflicts between flags that are chosen by the build system
and flags that are set by the user.

The feature added in #4611 is currently broken. This commit fixes the
behavior of the command and adds unit tests to ensure the basic semantic
is maintained.

It also changes slightly the behavior of Spec.concretized to avoid
copying caches before the concretization (as this may result in a
wrong hash computation for the DAG).

- Generating the HTML from for >2300 packages from RST in Sphinx seems to
  take forever.

- Add an option to `spack list` to generate straight HTML instead.

- This reduces the doc build time to about a minute (from 5 minutes on a mac laptop).

* Vendor ordereddict for python2.6 only

This commit substitutes the custom module 'ordereddict_backport' with
the more known 'ordereddict' and vendors it only for python 2.6. Other
supported versions of python will use 'collections.OrderedDict'.

* Use absolute imports also for python 2.6

See PEP-328 for more information on the subject

* Added provenance of vendored ordereddict

* ipopt: add version 3.12.8

* ipopt: allow linking with metis 5

* ruby: fix +openssl & +readline variants

Fix "unqualified variable spec['openssl']" error in the ruby package
that arises when trying to install the `+openssl` variant by
referencing the `spec` field in the `Ruby` class. A similar error
arises when trying to install the `+readline` variant; this error is
also fixed by this patch.

* ruby: make +openssl variant default to on

Ruby's gem command will fetch gems from HTTPS resources by default
(e.g., gem install bundler). Without openssl, request to fetch gems
bounce back with the error

```
ERROR:  While executing gem ... (Gem::Exception)
    Unable to require openssl, install OpenSSL and rebuild ruby (preferred) or use non-HTTPS sources
```

Without the ability to install gems -- required for some spack
packages -- the ruby installation has limited utility for many users.

* ruby: update rubygems ssl cert to fix ssl errors

The SSL certificate bundled with Ruby 2.2.0 is outdated, so e.g., `gem
install erubis` will fail with an SSL certificate error. This commit
installs the updated SSL certificate to the proper directory so that
gems can be downloaded and installed from RubyGems.

The url in graphviz has been fixed and its version has been 
updated to the latest available (2.40.1). Added variants for 
expat, qt, gtk+ and ghostscript.

* py-fparser: parser for Fortran 77..2003 code

* py-fparser: guard against external pytest.ini

* py-fparser: define 'develop' version as latest master branch

* py-fparser: fetch tagged versions from git repo

* py-fparser: add latest release 0.0.6

* py-fparser: whitespace adjustments for flake8

* py-fparser: inherit python dependency from PythonPackage

* py-fparser: rely on spack to resolve sub-dependencies

* py-fparser: try type='test' for py-pytest

* py-fparser: fetch release tarballs instead of git commits

* py-fparser: test deptype is available, remove comment

* py-fparser: limit versions that use py-six

* py-fparser: version ranges do not need a lower bound

* r-rappdirs: Create new package.

* r-rappdirs: Add version constraints.

* qt: move licence acceptance from qt3krell.patch to qt3accept.patch

* qt: ensure that ptrdiff_t is defined for qt@3.3.8b

* qt: disable webglplugin for qt@5.10~opengl

* qt: depend on libxext (for qt@3 and @4)

* qt: avoid X dependencies on darwin platforms

* Revert "qt: avoid X dependencies on darwin platforms"

This reverts commit 05ce08de94be1e02d7e2f2dae0c1ae59baa3f65a.

* qt: limit range of versions depending on libxext

* Fix installation of bash-completion

* use run_before decorator instead of overriding install method

* Update py-backports-functools-lru-cache to 1.4

* fix old url

Also updated all the sums from previous versions