[occa] /omp/occa mode

[occa] okl return => continue

[occa] kernel tile fix

[occa] MFEM ex1 working

Add basic doxygen docs (slightly incomplete)

Port docs from report; can we render using LaTeX?

Merge branch 'jed/travis' [PR #16, resolve #15]

* jed/travis:
Basic Travi-CI with no dependencies

Basic Travi-CI with no dependencies

Merge pull request #11 from CEED/occa-backend

OCCA backend [occa-backend]

tests/tap.sh: Recognize backend failure to find resource and report SKIP

OCCA: fail when requesting GPU resource but getting Serial

Makefile: make PROVE_OPTS configurable

Makefile: preferred abspath handling

Makefile: resolve abspath for rpath

Allows executables to be run from any directory.

Build path to ceed-occa-restrict.okl instead of hard-coding

[occa] mfem example except L2 projection

[occa] kRestrict kernel

[macosx] test fix

Fix the MFEM example build plus a few other fixes and tweaks in the
OCCA backend.

Merge branch 'occa-backend' of github.com:CEED/libCEED into occa-backend

[make] master and fix occa with new API

Provide a default location for OCCA. Check if the OCCA library file exist
before enabling OCCA.

Merge branch 'master' into occa-backend

[style] *Occa to *_Occa
[occa] moved 'device' global var to ceed private structure
[style] dbg to CeedDebug, moved to ceed-impl.h/ceed.c

Mention prove in the README