BF: Releasing vlc related ctypes obj's

Hopefully this will fix the pygame crash at end of movie playback demo.

Also ENH:
- no audio support option (took 5 minutes)

- function can be passed as a kwarg to the movie __init__ , which will
be called each time a frame is decoded.
Callback MUST take the form:

def myFrameProcFuncName(frame_index, frame_data):
# frame_index : index in the video for the frame_data.
# frame data : a numpy array of
# (video_height, video_width, 3) shape, with the 3 being
# the r, g, b color channels for each pixel. element type is
# uint8, valid values being 0 - 255.

# Do what you want to the frame array; as long
# as the array returned has same shape as array arg.
# ....

# Callback MUST return the updated frame data array
# Returned array can be same frame_data array passed
# into func, or it can be a copy, as long as shape
# and dtype have not changed.
return frame_data