Initial commit of version 2.1.0

Initial commit of CADET on GitHub. This project is relocated from
SourceForge.net to GitHub. Development will now continue on GitHub.

Changes since the last release on SourceForge.net:
- Complete rewrite of the MATLAB interface (breaking change)
- Adds native MATLAB MEX interface
- Restructuring of file format (breaking change)
- Add LaTeX documentation to repo
- Change inlet specification to a proper spline (breaking change)
- Add regression test for selected benchmarks
- Simplify build process by distributing ADOL-C along with CADET
- Support Clang on Mac OS X
- Fix various bugs (32 bit errors in HDF5 related code)
- Fix and enhance git support in CMake scripts
- Add version info to binaries
- Add workaround for strange OpenMP parallelization problem