Fix infinite loop while viewing "EPG: Timeline" window

With invalid begin/end times, the for loop in GUIEPGContainer.cpp L#825 (https://github.com/xbmc/xbmc/blob/5f33d290e/xbmc/epg/GUIEPGGridContainer.cpp#L825) loops endlessly, freezing XBMC when the user views the "EPG: Timeline" window. Solve this by adding check for invalid end times.
dvdplayer: disallow hw accel of SD mpeg2's

They are many dvd rips with non profile conformant streams that just
give garbage when rune using the hw decoder.
Merge pull request #3395 from garbear/invalid-dates

Fix infinite loop while viewing "EPG: Timeline" window
Merge pull request #3417 from elupus/mpeg2sd

dvdplayer: disallow hw accel of SD mpeg2's
[confluence] fix white haze on texture in video OSD
Merge remote-tracking branch 'teamxbmc/master'
Merge branch 'master' into faster-zapping
ffmpeg demuxer: faster channel switching: import changes from @fetzerch
ffmpeg demuxer: faster channel switching: partial import of changes from @davilla for Pivos
Mainly documentation and better error handling

Source:
https://github.com/Pivosgroup/xbmc/commit/4abd884392526a5771b774fabe496618b1286b8a
https://github.com/Pivosgroup/xbmc/commit/b11bfc930742ac5005e22b2ab6c91527a38b3eb6