Mantis 4109

Add fade label support to CheckButton and ToggleButton.

Removed redundant statement (e.g. type casts) from related classes as well as fixing a potential null reference.
Unmount ISO for external movie player and check for nullorempty (Guzzi fix)
Merge branch 'master' of https://github.com/MediaPortal/MediaPortal-1
Mantis #4109: adjusted scrolling for ToggleButtons

Moved the code for starting scrolling long text strings from the Render() method to an own Focus() getter/setter method based on the one of GUIControl.
add Thumbnail to (re)add folder display for #selectedthumb
Merge remote-tracking branch 'remotes/origin/BUG-4170-Using_External_Player_prevents_Virtual_Drive_unmounting'
Merge remote-tracking branch 'remotes/origin/BUG-4174-selectedthumb_no_longer_displays_default_folder_icon_in_RecordedTV'
Updated references.xml for Titan to activate scrolling on check and toggle buttons
Merge branch 'master' of https://github.com/MediaPortal/MediaPortal-1
Merge branch 'refs/heads/BUG-4109-Scrolling_for_CheckButton_and_ToogleButton'

Conflicts:
	mediaportal/MediaPortal.Base/skin/Titan/references.xml