[FIX] merged _isNegative and _helperIsNegative to isNegative into basic module
[FIX] added missing include
[FIX] moved ZLIB_WINAPI to stream.h
Merge branch 'feature/stream-fixes' of https://github.com/weese/seqan into feature/stream-fixes
[FIX] fixed namespace issue
Merge branch 'develop' of https://github.com/seqan/seqan into feature/stream-fixes

Conflicts:
	core/include/seqan/stream/stream_compressor.h
	core/include/seqan/stream/zipstream/bgzfstream.h
	core/include/seqan/stream/zipstream/zipstream.h
Merge pull request #656 from weese/feature/stream-fixes

[FIX] fixed "comparison is always true" warning