Mesh modeling

- Delete all vertex groups from a Mesh (Ctrl-Shift-G menu)
- ALT+select face-loop on mesh with hidden faces ignored the hidden part. Also caused errors on deleting faces that way.
- Added Lattice vgroup support to shrinkwrap and simple deform modifier.
- Modifiers: Added Shrinkwrap Constraint

Curve/Surface modeling

- New per-vertex radius option was not always properly initialized.
  (Use Wkey to access the values)
- Most Surface (NURBS) tools in buttons didn't add undo pushes.

Physics

- Bugfix: Speed vectors/velocity data not working on ALL fluids.
- Added 'Particle System' entries as children of particle system modifiers in the
outliner. Clicking on one activates it and takes you to the object buttons.
- Particles: hair or child particles didn't react to density texture.
- Particles: reactor particles affected by a curve guide emit at a wrong position.
- Particles: over dozen of stability/consistency bugfixes

Particles, new Mesh effector surface option:

- Most mesh particle effectors can now have their effection point taken per particle as the nearest point on the mesh surface.
- This is activated with the "surface" button in the effector field panel.
- Activating the option adds a "surface" entry to the modifier stack where the state of the mesh is read from.
- Example www.youtube.com/watch

Material/Render

- Important note: Yafray removed as render option, use Yafaray now (python)!
- Alpha in environment map render was wrong for sky colors
- Added a new interpolation type for colorbands: Constant. This can be useful for toon shading etc. Example image.
- Updated the colorband display to show the correct interpolation within the editable gradient itself.
- Compositor, filter node, had shifted output when used on single-value buffers.
- Black dots appeared when use raytracing with multi-thread and material nodes
- Halos for objects (not particles) now use the alpha "map-to" texture channel
- Texture nodes could enter eternal loop when connecting in cycles
- Key Alpha render now works for Motion Blur
- Sequencer: scaling images gave unwanted banding and shift of color (introduced in 2.48)
- Scrub frames (LMB) in Sequencer image window works again.
- Map a texture to Material Ambient factor now works
- when using node material, transparent shadow did not work
- Sequencer: Added custom proxy file storage

Node Editor

Now the Node Editor supports all non-Material Texture NodeTrees too, with three extra
icon buttons to define which:

- Active Object: for textures linked to Materials or Lamps
- World: textures from Scene world.
- Brush: textures from active Brush

The latter can only be set and used when in Paint or Sculpt mode:

- Paint mode: in Image window, Paint Tool panel, set active brush
- Sculpt mode: in EditButtons, Texture panel, select empty slot, add texture.

Note that refreshes of previews in Node Editor is not always happening on
switching contextes. Just click a socket to refresh view.

Animation

- Two important crash fixes in Armature Proxy usage in combination with Undo.
- The Bone-roll mess in transform get fixed. Since roll is based on an automatically calculated up axis, transforming bones would mess up bone orientation. The new code automatically adjusts the roll value to keep bone orientation as consistant as possible. That works all around in transform for all transformations.
- Added a new Timeline menu entry: Playback -> Sync Playback to Frames/Sec.
- Playback of an animation now uses the step value in the render panel (or -a -j).
- "Clear user transform" did not work as described, it is supposed to restore selected bones to the transforms defined by Actions/NLA, not back to rest position. If there's no Action it resets to rest position.
- Duplicating an armature, with constraints having a local Ipo, didn't make a copy of this Ipo too, frustrating its drivers too.

UI

- Grease Pencil crashed after duplicating a screen-area, and deleting a layer from the original screen-area.
- Python script feature request: now space handlers can report release events too.
- OpenGL specular now gets the correct view vector in perspective mode. Works in both the 3d view and game engine
- File browser: now sorts files alphabetically based on "natural" number ordering.
- Linux: Copy/Paste text from or into Blender wasn't working in cases
- Several GLSL updates for more support of Material/Light features
- Windows bug fix: Mouse wheel zoom lost after rendering (opening window).

Various

- Updated ffmpeg to release version 0.5
- Sound now supported for OSX Intel build
- Plenty of fixes in Sequencer ffmpg support and audio...