WinGui: Fix an issue with the Seconds mode (not setting end point correctly)

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5762 b64f7644-9d1e-0410-96f1-a4d463321fa5
WinGui: Another small fix around point to point mode setting of start and end points.

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5763 b64f7644-9d1e-0410-96f1-a4d463321fa5
WinGui:  Fix around logging when the TextWriter is closed and Removed an unneeded error handler in Interop library. (libavformat mp4 muxer does not have a large file size option)

git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@5764 b64f7644-9d1e-0410-96f1-a4d463321fa5