Create an 'active' filters buttonlist which can be used for informational
purposes in the schedule editor.

Allow the filters buttonlist to be used on the main schedule editor view.

(cherry picked from commit 6a87bbda31a209398c44fa92761ec0d5d9784954)

Conflicts:
	mythtv/programs/mythfrontend/scheduleeditor.cpp
Honor the disabled state in buttonlist items.

(cherry picked from commit eb17a56d137c76cf8a84c43d192b72d93338ccf5)
(cherry picked from commit 73037c4ecd36eaf7ff35504f524344d1ab5a3f18)