Make curve decimation only take into account the selected curve points

Previously the decimation would take the whole curve into account when
decimating and not just the selected part.

This also contains various smaller bug fixes for the fcurve decimation.

Reviewed By: Sybren

Differential Revision: http://developer.blender.org/D6286

release/scripts/startup/bl_ui/space_graph.py

@@ -113,6 +113,7 @@ class GRAPH_MT_view(Menu):
         st = context.space_data
 
         layout.prop(st, "show_region_ui")
+        layout.prop(st, "show_region_hud")
         layout.separator()
 
         layout.prop(st, "use_realtime_update")
@@ -290,7 +291,14 @@ class GRAPH_MT_key(Menu):
         layout.operator_menu_enum("graph.easing_type", "type", text="Easing Type")
 
         layout.separator()
-        layout.operator("graph.decimate")
+        operator_context = layout.operator_context
+
+        layout.operator("graph.decimate", text="Decimate (Ratio)").mode = 'RATIO'
+        # Using the modal operation doesn't make sense for this variant as we do not have a modal mode for it, so just execute it.
+        layout.operator_context = 'EXEC_DEFAULT'
+        layout.operator("graph.decimate", text="Decimate (Allowed Change)").mode = 'ERROR'
+        layout.operator_context = operator_context
+
         layout.operator("graph.clean").channels = False
         layout.operator("graph.clean", text="Clean Channels").channels = True
         layout.operator("graph.smooth")