Correct Player.PlayPause behavior

In current implementation using play parameter as boolean won't force the playerspeed to 1 as it should.
This PR correct this so that using a bool parameter act as the toggle and provide the same behavior as GUI or EventServer.
refresh the correct video viewed in the video info dialog (fixes #13676)
Merge pull request #2308 from Montellese/13676_video_refresh

refresh the correct video viewed in the video info dialog (fixes #13676)
CFileItem: extend Copy() with an optional "copyItems" parameter (true by default) to be able to only copy the properties of a list without the items
video library: fix handling of watched episode count in custom tvshow nodes (fixes #14097)
Merge pull request #2311 from Montellese/14097_episode_count

video library: fix handling of watched episode count in custom tvshow nodes
Marked DllDynamic::IsLoaded() as const
Added DllDynamic::GetFile() to complement DllDynamic::SetFile()
Merge pull request #2301 from Tolriq/CorrectPlayPause

jsonrpc: correct Player.PlayPause behavior