[AML] Remove dependency on libamplayer and amffmpeg
[AML] Fill audio packets completely when resampling to prevent 'audio data unaligned' kernel warnings
[AML] Use fpsrate and fpsscale instead of rfpsrate and rfpsscale to detect framerate
[DVDPlayer] Fix incorrect frame rate detection of some videos with variable frame rate.

Use FFMPEG's r_frame_rate, if it as valid, as a video stream frame rate, otherwise use avg_frame_rate.
Also remove CDVDStreamInfo.rfpsscale, CDVDStreamInfo.rfpsrate, CDemuxStreamVideo.irFpsScale and CDemuxStreamVideo.irFpsRate,
they are not needed anymore.
[AMLCodec] Always use the SYNC_OUTSIDE decoder flag for most smooth playback of H264 video
[Settings] Save settings only if they were modified after last save

This prevents from multiple saving the same settings and helps to resolve
the issue on Amlogic G18REF TV-boxes when setiings may be lost after a poweroff.

On G18REF When you press the red button on the remote the system receives a signal that power
is about to off. XBMC always writes guisettings.xml before exit, and the same settings
may be written several times from different places in code. But the power gets turned off
before the system completes all shutdown procedures. There may be the case that guisettings.xml
is written half-way and couldn't be read upon next boot, so the XBMC creates a new one with
default settings.

With this fix the settings will be written at exit only once, minimizing the risk of being lost.