added more flexible colorspace conversion method.
added method to get numpy array from frame, similar to pil.image from frame
example show frames using numpy and openCV
using first argument as video file path in example - to match other examples.
fixed typo
made frame.time_base accessible to user.
removed av_frame_get_best_effort_timestamp
added _flush_decoder_frames method
None flushes codec, like encoding
check frame counts
check frame counts against stream.frames
set pts of flushed frames if possible
matched dranger method pts closer
added frame seek example
seeking tests
Initialize global network.

This is recommended, since it avoids the overhead of implicitly doing
the setup for each session.
Support PIL or Pillow.

Clean up examples so that Pillow can be used rather than the deprecated
PIL library.
Add file probing tests
Add size property to InputContainer

Could be argued whether to use python internal libraries, but FFMPEG
already has an API for size which will work for both local and network
files.
Add max_bit_rate to Stream

FFMPEG does not return a bit-rate for mpeg2 video streams. When this
happens you could fallback to the max_rate.

Libav however does return a bit-rate for mpeg2.

Tests added which handle differences in results between lib and ffmpeg.
Add width and height read properties to Stream.