Fix incorrect usage of S_IFDIR flag
[pvr] fix: last watched timestamps won't update after channel switch

As we only update the last watched timestamp of the current playing channel before a successful channel switch is performed we sometimes continue the wrong last watched channel and group.
[vobsub] always set correct source value when creating vobsub stream in demuxer
[vobsub] set filename2 on all vobsub streams that are part of the external file
[vobsub] don't prioritize external VOBSUBs over external SRTs
[vobsub] ensure external vobsubs included in the idx file are all marked as (external)
set deinterlace mode to AUTO as default
fixup: drop const for CPVRChannel
linuxrenderer: remove obsolete includes
linuxrenderer: use pragma once instead of outdated ifdef
[vobsub] exclude archived .sub files from filename when not starting with base video name
SysInfo: add GetAppName()
SysInfo::GetUserAgent: Change "XBMC" -> "Kodi"
Merge pull request #5384 from Karlson2k/user_agent_upd_03
Merge pull request #5414 from Voyager1/vobsub-fixes

VobSub fixes
Merge pull request #5432 from FernetMenta/linuxrender

linuxrenderer: drop obsolete includes
Merge pull request #5418 from FernetMenta/deint

set deinterlace mode to AUTO as default
Merge pull request #5386 from Karlson2k/fix_s_ifdir_01

Fix incorrect usage of S_IFDIR flag
Fix: missing space for Kodi forks. Thanks to @notspiff
Update tests for SysInfo::GetUserAgent(). Thanks @notspiff