extern C added for compatibility with C++ code
Merge pull request #16 from jmmut/develop

Fixed bug in Sconstruct when changing compilers.
Moved folders common-libs, bioinfo-libs and math. #17
Added SConscripts to the 5 directories in c/src. #17
Fixed SConscript to compile all 5 libraries into libhpg.a #17
Improved SConstruct to build lib in c/build/. #17
Moved samtools, htslib and jansson to third_party. #17

jansson is not a submodule.
Moved sqlite to third_party. #17

Couldn't make the submodule work, so it's a plain copy.
also, moved jansson from libcommon.a to libbioformats.a.
Moved argtable and improved SConscripts. #17
Moved libconfig to third_party. #17
Final clean up of the refactoring. #17
Moved cprops to third party. refactoring: #17.
Fixed support to intel compiler. #17
Merge branch 'jmmut-feature/cplusplus' into feature/cplusplus. Resolves #17
Added support to read bgzipped files ( #14 )

It uses htslib.
Basic reading of plain VCF file and call to Ragel state machine
First version working with a full file
Some parsing rules flattened, and method 'parse_line' renamed to 'parse'
First version of configurable parsing and validation: ignore or store errors, stop or continue after one error is found
Support for aggregated VCF files