Tracking: Expose Filter Tracks operators to the Cleanup panel

Not totally happy with this, but it's better than nothing for until
we've got real outlier detection. Also made it more cleat how exactly
filtering happens, so users don't expect something the operator is not
intended to do.

release/scripts/startup/bl_operators/clip.py

@@ -125,6 +125,7 @@ def CLIP_default_settings_from_track(clip, track, framenr):
 
 
 class CLIP_OT_filter_tracks(bpy.types.Operator):
+    """Filter tracks which has weirdly looking spikes in motion curves"""
     bl_label = "Filter Tracks"
     bl_idname = "clip.filter_tracks"
     bl_options = {'UNDO', 'REGISTER'}

release/scripts/startup/bl_ui/space_clip.py

@@ -467,6 +467,7 @@ class CLIP_PT_tools_cleanup(CLIP_PT_tracking_panel, Panel):
         layout.prop(settings, "clean_frames", text="Frames")
         layout.prop(settings, "clean_error", text="Error")
         layout.prop(settings, "clean_action", text="")
+        layout.operator("clip.filter_tracks")
 
 
 class CLIP_PT_tools_geometry(CLIP_PT_tracking_panel, Panel):