Remove Synchronize redundant functionality and replace with the standard CSingleLock.
CurlFile: request UTF-8 as preferable charset
CurlFile: don't set 'keep-alive' as cURL do this internally
Some web servers can't properly handle duplicated header value.
[potential-fix] I ran into a few hangs-on-exit that this MAY help address. This allows the thread that's waiting for python threads to exit to raise python system exceptions within the threads it's trying to get to exit.
Merge pull request #3465 from jimfcarroll/fix-some-hang-on-exits

Potential fix for one case of hanging-on-exit
Merge pull request #3418 from Karlson2k/charsetconverter_rework_04

CharsetConverter rework - part 04
[addonmgr] query addon disabled state once and cache it (fixes #14122)

This implements DisableAddon and IsAddonDisabled in AddonMgr. Both functions will trigger the database routines
and cache the current addon state instead of doing the database query again. In case the disabled cache does not
know about the current state the database routine will be used to retrieve it.
Merge pull request #3457 from davilla/nuke-amplayer

droid: remove legacy amlplayer
Merge pull request #3461 from vdrfan/addonmgr_cache

[addonmgr] query addon disabled state once and cache it (fixes #14122)
FIX: crash with missing controls in DialogKaiToast
dvdplayer: only disable SD mpeg2 for DXVA, seem vaapi and vdpau are ok

Partial revert of: f02ac98fe8851aac15245792b9798813fbd06c1a
Merge pull request #3460 from FernetMenta/vdpau

vdpau: check for GL_NV_vdpau_interop in open
FIX: [droid] (re-)fix sftp/ssh
[GUIInfoManager] Add VideoPlayer.AudioLanguage infolabel.
[DVDPlayer] Set CMediaSettings::Get().GetCurrentVideoSettings().m_AudioStream on open/set.
Merge pull request #3164 from koying/fixdroiddvdiso

FIX: [droid] fix dvd playing on > 2Gb iso
Merge pull request #3025 from koying/fixdroidrestorevolume

FIX: [droid] restore system volume on exit
depends: use -isystem instead of -I to add system includes

This avoids libs using already installed system headers when
building themselves.
Merge pull request #3469 from koying/fixdroidsftp

FIX: [droid] (re-)fix sftp/ssh
Merge pull request #3454 from tru/fix_coreaudio_mixmapping

[AE/CA] Fix coreaudio mixmapping