CFile: fix null pointer dereference in Stat() and Write()
[vfs] CFile: add null pointers checks
AE: re-add setting normalizelevels, formally inverted and known as boost volume on downmix
videodb: add SetDetailsForMovieSet
jsonrpc: add VideoLibrary.SetMovieSetDetails
Merge pull request #3555 from FernetMenta/aefixes

AE: re-add setting normalizelevels, formally inverted and known as boost...
[rbp/omxplayer] Fix crash on stopping mp3 playback with amplification

There is a race condition where we can try to adjust volume after deinitialation
when amplification is enabled, causing a seg fault.
Merge pull request #3561 from popcornmix/amp_deinit_crash

[rbp/omxplayer] Fix crash on stopping mp3 playback with amplification
adds left, top, right, bottom, centerx, centery to the list of xml nodes that can take constants
support positioning dialogs via <left> and <top>
ensure library:// folder URLs have slash at end
Merge pull request #3534 from Karlson2k/cfile_fix_01

CFile: fix null pointer dereference
Merge pull request #3556 from Montellese/jsonrpc_setmoviesetdetails

jsonrpc: add VideoLibrary.SetMovieSetDetails
settings: add CSetting::Clone()
CSettingAddon/Path: implement Clone()
settings: add CSettingList implementation
settings: add GetList()/SetList() to CSettingsManager
settings: add wrapper for GetList()/SetList() to CSettings
WIP: settings: add multiselect support to list control
TMP: dummy list[string] setting