[WIP] CEED 2.0 (#10903)

* Initial commit for v2.0 of the CEED software suite.

* Update Nek packages and gslib

* Help spack concretize the hypre version for ceed-2.0.

* Fix nekcem install error

* Add support for gfortran v8 in nek5000 and nekcem.

* Split Nek5000 into Nek5000 and Nektools

* Get Nektools to build fine in Theta

* Fix travis failure: remove unused 'import numbers' from nek5000.

* Check for gfortran if it is wrapped

* Tweak the detection of gfortran in nek5000.

* Fix Nek packages to add -std=legacy when FC=gcc

* spack install ceed~petsc works fine on Theta

* Fix flake8 errors

* Fix more flake8 tests

* Fix an import issue

* Tweak the suite-sparse package to avoid interaction with existing system
installations of suite-sparse.

* petsc: update superlu-dist dependency

* Updates in the packages: occa, libceed, and ceed.

* In the libceed package, explicitly tell nvcc which host compiler to use.

* Fix python formatting.

* Simplify the test for gfortran in nek* packages.

* ceed: 2.0 uses petsc@3.11.0

* hpgmg-0.4; use from ceed@2.0.0

* Update the hypre dependency for ceed 2.0.

* Disable the superlu-dist dependency (through hypre) when using a
+quickbuild of ceed 2.0.

* petsc-3.11.0: add xlf fix

* nekcem: has a build dependency on Python 2.7+

* hpgmg: better setting of compiler options and use python for configure

* libceed: use v0.4 tag

* libceed: fix 0.4 release oops (pkgconfig version)

* Add a patch for magma-2.5.0 that brings it up the current 'master'.

* In the mfem package, install the examples, miniapps, and data under
$prefix/share/mfem.

* In the magma package, apply a patch to v2.5.0 that disables
magma_sparse - for testing purposes.

* In the magma package, link the 'magma' library with the
'nvToolsExt' library.

* In the magma package, update the 'magma-2.5.0.patch' with the latest
commits from the magma source repository. Also, remove the library
'nvToolsExt' from the 'magma-2.5.0-cmake.patch' - now it is not
needed.

* In the magma package, disable OpenMP when using v2.5.0 with the
IBM XL compiler.

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* In the mfem package, add version for the 'laghos-v2.0' tag; also,
prefix the versions `laghos-v*` with their respective development
version numbers -- this way they are properly ordered within spack
relative to the official numbered versions.

* petsc: add version 3.11.1 (#11179)


(cherry picked from commit 1eab6e3c)

* ceed-2.0: use petsc-3.11.1

* this-is-so-dumb.f -> empty.f