make compatible with cx_freeze in gui32 mode
fix import of os for other systems than win
add threads parameter to speedup conversion
very tiny changes
Merge branch 'master' of https://github.com/bobatsar/moviepy into bobatsar-master
Merge branch 'bobatsar-master'
New configuration management. made FFMPEG_BINARY etc. modifiable at runtime.
Included ffmpeg_params. Hope PEP8-related conflicts didn't break anything

Conflicts:
	moviepy/video/VideoClip.py
	moviepy/video/io/ffmpeg_writer.py
Merge branch 'aherok-master'