Add a BrotliCompress() method to the public encoder API
that uses the BrotliIn and BrotliOut classes and use
that in the 'bro' command-line tool.
Use the streaming api in BrotliCompressBuffer() and
BrotliCompressor::WriteMetaBlock().
Use the appropiate hashers for quality <= 9.
- Distinguish between CC/CFLAGS, CPP/CPPFLAGS and CXX/CXXFLAGS.
Do not store compiler flags in CPPFLAGS, which is for preprocessor,
and do not try to link files using a preprocessor.
- Use COMMON_FLAGS for flags that are for both C and C++.
- Drop -m64 flag which is wrong on 32-bit systems.
- Use $(MAKE) instead of make, so that parallel building works.
