use max frames per slice suggested by apple for play audio after lock screen on ios
adjust audio engine can auto-resume from suspend state for ios.
add UnPause and real Pause method on ApplicationMessenger
change to use PRINT_SIGNATURE() for object-c common method trace, add debug log for important methods
add background mode/flag in the main Application and used in ios
accept control from ios control bar (on lock screen and left of multi-task bar)
support show nowPlaying item info on ios lock screen and media control bar
handle ios interruption and app active/inactive/bg switch perperly.

also suspend audio engine when needed, which affect the status of
play-pause button on ios media control bar.
disable ios network auto-suspend after lock and screen goes dark
Add codec, bitrate and channels to the "audiostreams" result of Player.GetProperties.
This makes Player.Audio.Stream and Player.Audio.Stream.Extended equal. Therefore Player.Audio.Stream.Extended is dropped.
Merge pull request #2224 from ace20022/jsonrpc

[json-rpc] Add the possibility to query more info from any audio stream.
cosmetic cleanup
fixed, valid avcC atom path on open
[osx/vda] refactor to use CBitstreamConverter class
[PulseAEStream] Possible null pointer dereference.
[AE] [AESinks] Cleanup/init vars, check for return values and performance improvements, e.g., call by ref, pre-/post-incr.
cleanup includes and ifdefs for DVDVideoCodecVDA
Merge pull request #2380 from ace20022/warnings

[AESinks] Fix things found by Cppcheck
[IOS] do not keep network alive in idle state (paused or stopped).
[IOS] media controlbar add support seek forward and rewind.