* py-markdown: Add new package for python-markdown.

* py-markdown: Added restrictions on Python version.

* py-markdown: Removed upper-limit on compatible Python versions.

* py-markdown: Reinstated upper bound on Python version. Also fixed small formatting error.

* build fixes for openblas

* avx2 in openblas nnot supported with older gcc

* merge fix for openblas

* graphviz: fixed build error due to specifying ltdl lib but not include.

* graphviz: Fixed dependencies on libtool and expat.

* init nfft 3.3.2 package file

* shorten comment line

* Always default to +mpi

* Always default to ~X

* MakefilePackage: changed build_args and install_args for consistency with #2464
openblas: derives from MakefilePackage

* MakefilePackage: changed default edit behavior

Changes any to a string to avoid <built-in function any> being
incorrectly added to target in compilers.yaml.

Fixes #2554

Texlive is *live*, they update the contents of their tarball on a whim.

Here's the current one.

* Add python cdo support

* Correct pypi url

* Corrected a blanck space that was failing CI

* Corrected url that was failing CI

* Following @alalazo indications, Write this line wrapping it around 80 chars to pass Travis

* Added cdo package depency

Fixes issue #2578

A couple of updates for python package.

* Better cxx11/14 flags for GNU/Clang/Intel

- GCC 4.8 only supports -std=c++1y for C++14
- Use CMake's rules for AppleClang to set cxx11 and cxx14 flags based on
  Apple Xcode/LLVM version
- Use CMake's rules for Intel to add support for cxx14 flags based on
  Intel version.

* Add cxx17_flag property

Implement property in compiler for c++17 as per those for c++11/14.
Add concrete support for GNU/Clang:

- Return -std=c++1z for GCC 5 and above per GCC documentation
- Return -std=c++1z for Clang 3.5 and above per Clang documentation
- Return -std=c++1z for Apple LLVM 6.1 and above per CMake's rules

* Added support for xSDKTrilinos package

* Updated xsdktrilinos/package.py for PR review

* Added trilinos version # reqs to xsdktrilinos

* xsdktrilinos now uses CMakePackage

* Cleaned up xsdktrilinos/package.py

* Removed unused cxxflags from xsdktrilinos

* Removed unused sys import from xsdktrilinos

* Update `spack setup` and `spack graph` to be consistent with c557e765 and 9347f869.  Fixes #2316.

* Added another "fix" necessary to make `spack setup` work.

* Added another "fix" necessary to make `spack setup` work. (reverted from commit 7f0d3ecb38c97ec00491d7cd66b4266e3018b1ca)

* Add freetype dependency on bzip2

* Switch package with an install method for the docs

* Add documentation for repositories and namespaces.

* Update and extend repository documentation per review.

- Also add `-N` argument for `spack spec`

* atlas: fix lapack stage path

* atlas: add a few links to other package managers