Killed silly modal PoseMode mode! :)

- PoseMode now is a state Armature Objects can be in. So, while in PoseMode
  for an Armature, you can just select another Object or Armature.
- The old PoseMode options (transform, insert keys etc) are accessible
  with making the Armature Object 'active' (and have object in PoseMode).
- At this moment no multiple Poses can be transformed/edited at the same
  time.
- The old hotkey CTRL+TAB, and view3d header menu, still work to set an
  Object's PoseMode

It was quite a lot recode, so tests & reports are welcome.

Oh, as a bonus I added Lasso Select for Bones in PoseMode! It selects using
only the line between root and tip of the Bone.

source/blender/src/drawscene.c

@@ -70,8 +70,6 @@ void set_scene(Scene *sce)		/* also see scene.c: set_scene_bg() */
 	/* ending all modes */
 	if( G.obedit) 
 		exit_editmode(2);
-	if(G.obpose) 
-		exit_posemode(1);
 	
 	if(G.f & G_FACESELECT)
 		set_faceselect();