[confluence] replace subtitle flag icons with new ones

As discussed in #3552, this replace the subtitle flag icons with new
32x32 pixel icons from https://www.gosquared.com/resources/flag-icons/

This also fixes some wrong flags like uk. It's Ukrainian not United
Kingdom.
[url] don't run ValidatePath() on hostnames where the protocol has an encoded hostname. fixes #14699
[dxva] fixup: anaglyph 3d
videodb: SQL query cosmetics in CleanDatabase()
videodb: use faster (NOT) EXISTS instead of (NOT) IN CleanDatabase()
videodb: handle files whose source is completely gone differently during clean
[confluence] texture changes for epg timeline view
add RSS feeds from our addon website
[release] version bump to 13.0 alpha11 as we start new merge window
fix crash loading JPEGs where m_cinfo.scale_num was set to 9 due to not finding a suitably sized scale factor. Thanks to tscheck
Merge pull request #3708 from Montellese/videodb_clean_offline

videodb: better support for sources being temporarily offline during a library clean
context menu: move "Remove from library" to "Manage..." sub menu
context menu: use string-based media type detection instead of VIDEO_DB_CONTENT_FOO
context menu: add Manage... sub-menu to movie sets
context-menu: add "Manage..." sub-menu to tags
CGUIDialogVideoInfo: add NULL-pointer and other sanity checks
context menu: move "Scan for new content" to the very bottom for tvshows (same as for video sources)
context menu: move "Play" to the top (for folders) as it should always be the first option
FIX: External Player support for Android. See: http://forum.xbmc.org/showthread.php?tid=175341
FIX: [stagefright] partial revert of 645010e ; causes "upside-down" videos