weight paint UI

- added back 2.4x 'Vgroup' option to the UI, restricts painting to verts already in the group.
- remove 'All Faces' button in weight paint mode. it doesn't do anything.

release/scripts/modules/animsys_refactor.py

@@ -532,8 +532,6 @@ data_2_56_to_2_59 = (
     ("ShaderNodeMapping", "minimum", "min"),
     ("ShaderNodeMapping", "clamp_maximum", "use_max"),
     ("ShaderNodeMapping", "clamp_minimum", "use_min"),
-    ("VertexPaint", "all_faces", "use_all_faces"),
-    ("VertexPaint", "spray", "use_spray"),
     ("ParticleEdit", "add_keys", "default_key_count"),
     ("ParticleEdit", "selection_mode", "select_mode"),
     ("ParticleEdit", "auto_velocity", "use_auto_velocity"),