2.6 UI:

* Hide Modifier and Contraint Panel header, this gives a bit space.
As it's the only panel in these context tabs it does not make sense to close them anyways.

release/scripts/startup/bl_ui/properties_data_modifier.py

@@ -25,6 +25,7 @@ class ModifierButtonsPanel():
     bl_space_type = 'PROPERTIES'
     bl_region_type = 'WINDOW'
     bl_context = "modifier"
+    bl_options = {'HIDE_HEADER'}
 
 
 class DATA_PT_modifiers(ModifierButtonsPanel, Panel):

release/scripts/startup/bl_ui/properties_object_constraint.py

@@ -822,6 +822,7 @@ class ConstraintButtonsPanel():
 class OBJECT_PT_constraints(ConstraintButtonsPanel, Panel):
     bl_label = "Object Constraints"
     bl_context = "constraint"
+    bl_options = {'HIDE_HEADER'}
 
     @classmethod
     def poll(cls, context):
@@ -846,6 +847,7 @@ class OBJECT_PT_constraints(ConstraintButtonsPanel, Panel):
 class BONE_PT_constraints(ConstraintButtonsPanel, Panel):
     bl_label = "Bone Constraints"
     bl_context = "bone_constraint"
+    bl_options = {'HIDE_HEADER'}
 
     @classmethod
     def poll(cls, context):