Fix AirTunes pts accuracy
[rbp/omxplayer] Fix audio volume jumps when switching tracks

When the global volume has been set low, and a sequence of tracks are being played, there are complaints of occasional jumps to full volume.
This is down to a race condition where the volume request can arrive at OMXAudio before it has been initialised.
The fix is simple, don't send the volume change until m_CurrentAudio.started.
Merge pull request #2641 from popcornmix/fix_volume_jump

[rbp/omxplayer] Fix audio volume jumps when switching tracks
Merge pull request #2625 from hmis/AirTunes_pts

Fix AirTunes pts accuracy
[libdvd] - added missing patches
[Fix] http protocol options seekable=0 now finally works.
Merge pull request #2644 from ulion/fix_seekable_protocol_option

[Fix] http protocol options seekable=0 now finally works.
GUIFadeLabelControl: fix control being marked as dirty when label stays empty

If used infolabel will return empty string on first use, m_shortText will never be evaluated. If m_shortText is set to false control is marked as dirty so if used infolabel is empty control will be wrongly marked as dirty.
FIX: log spamming
Typo fix in README.raspberrypi
Merge pull request #2650 from robinbijlani/patch-1

Typo fix in README.raspberrypi
Merge pull request #2646 from koying/fixlogspamming

FIX: log spamming
[Cosmetic] Fix indentation.
[LangCodeExpander] Add "Abkhaz" to the ISO 639-2 list.
[LangCodeExpander] Fix German and Portuguese ISO 639-1 language code and add "Abkhaz".
Merge pull request #2651 from ace20022/lang_codes

Fix and extend ISO 639 lists
FIX: Allow "Scan for new content" on folders
Merge pull request #2645 from koying/fixscanfolder

FIX: Allow "Scan for new content" on folders