Changes suggested by @r-lyeh and @anthrotype.
- Use a portable simple PRNG instead of rand_r()
- add missing <assert.h> include
- disambiguate log2() argument type
- remove endian.h include from write_bits.h
The new interface of the backward reference search
function makes it possible to use it in a streaming
manner.
Using the advanced cost model and static dictionary
can be turned on/off by template parameters.
The distance short codes are now computed as part of
the backward reference search.
Added a faster version of the Hasher.
