Changed logic to get Position from Stream and not from Mixer.

Now FF and REW works with larger Buffers
Mantis #4469 Webstream Radio fix.
Mantis #4473: added wikipedia support
Added additional time on Reverse seeking to prevent troubles on lower speeds
Merge remote-tracking branch 'remotes/origin/BUG-4469-Internet_Radio_Stream_has_to_be_selected_twice'
Merge branch 'BUG-4466-FF_and_REW_produces_wrong_result_with_standard_BASS_Player'
Merge branch 'BUG-4473-Wikipedia_support_in_Titan'
Merge branch 'master' of https://github.com/MediaPortal/MediaPortal-1