Attempt to bugfix

Fixed ifndef on video_background_segm.h; was the same as the one on
video_tracking.h.
Now throws error for wrap() method on video_background_segm.h
Fixed BackgroundSubtractorMOG

Removed use of method wrap in video_background_segm.h that was removed
from my_functions.h on
https://github.com/shimat/opencvsharp/commit/c7f878f40604b70f6ec3bbe9e8fa849dcceb3524#diff-bac678820711126b649654b3f96eb929
Pull request
Merge pull request #46 from codingTornado/master

Fixed a bug on video_background_segm.h
Added KeepAlive
Merge remote-tracking branch 'remotes/origin/master' into CPlusPlus-Improvement-stitching