Add igzip_lib.pyx with access to the igzip_lib api #68
Description
This will have:
- compress
- decompress
- compress_stateless
- decompress_stateless
- IgzipCompressor
- IgzipDecompressor
With the compressor and decompressor object resembling those from bz2 and lzma modules. These can be used in igzip to reduce the overhead caused by unconsumed_tail.
Also igzip_lib has many more fine-grained settings for headers and trailers, which can be used to great effect (i.e. write no header, but do write a trailer). This can be used in igzip.compress and igzip.decompress.