Removed config.h and moved macros into taglib_config.h
Prefixed public variables
Separated public and private config.h
Removed RefCounter implementation from a public header
Removed TAGLIB_HAVE_STD_WSTRING macro that affects the public ABI
Fixed mismatched macro names
Merge pull request #187 from TsudaKageyu/config

Removed config.h and moved macros into taglib_config.h