Documentation for the headers
Implemented support for lz4 and future snappy
fix including lz4 sources
fix prefixing in the tests
allow to use snappy
add all compressors to the single and suite tests
fix segfault when missing codec
bail out if no such codec
fix various typos
conditional compile support for snappy

This adds CMake support for conditionally compiling snappy support for blosc.
Should still be able to copy and paste sources, since HAVE_SNAPPY is only
defined via config.h, but will need an empty config.h... Not sure how to solve
that one yet.
only run snappy benchmark if lib was compiled with snappy support
Updated to the latest version of LZ4
Added support for Zlib compressor
Fixed (hopefully) a problem with buffer sizes with snappy
Uniformization of the decompression interface
Uniformization of the compression interface for LZ4
Added the zlib compression to the test (using 'single', not 'suite' which is too heavy)
Adding the license for LZ4
Added a message error when the decompressor is not available
Follow the conventions for the brackets