Add support for uploading .anim files.

Mostly works, but
indra/newview/skins/default/xui/en-us/floater_animation_anim_preview.xml
needs work (the 'Name:' should be at the top, not the bottom).

Also, it asks if you want to upload this as temporary. It shouldn't do
that.

indra/newview/llviewerobjectbackup.cpp

@@ -56,7 +56,7 @@
 #include "llappviewer.h" 
 #include "llassetuploadresponders.h"
 #include "statemachine/aifilepicker.h"
-#include "llfloateranimpreview.h"
+#include "llfloaterbvhpreview.h"
 #include "llfloaterbuycurrency.h"
 #include "llfloaterimagepreview.h"
 #include "llfloaternamedesc.h"