MythVideo gallery always sorts by filename

[Robert Tsai <rtsai1111>]

This is caused by the call to "video_tree_root->sortByAttributeThenByString(0);" in VideoGallery::fetchVideos(). Strictly speaking, removing that line is sufficient to provide the expected behavior of the MythVideo? gallery respecting the desired sort field (runtime, user rating, etc.).

However, I took the long way figuring that out :P. The attached patch does that, plus a bunch of cleanup:

• Remove unused and redundant member variables and methods from various classes.

• Remove the VideoBrowser?'s "suboptimal" use of getVideoListMetas.

• Add some comments.

• Perform parental-level filtering in the SQL query, rather than after the fact in fetchVideos().

• Add keypress handlers for browser and gallery for "HOME" and "END" (move to beginning and end of video list)

• Fix up gallery keypress handlers for pageup/pagedown to support wraparound navigation.

• Reverse up/down in browser to follow "document" navigation, to be consistent with current pageup/pagedown behavior. I am not trying to impose my own opinion of the way I think things "should" be, but I do think up/down should be consistent with pageup/pagedown (although for the record, I do think the "document" navigation paradigm is appropriate for the video browser).

[jdonavan]

(In [6809]) Big cleanup patch from Robert Tsai. Fixes problem with the gallery always sorting by name.

this closes #92