IK work-in-progress commit;

- Removed old convention that only allowed one "IK" connection for Bones
  in a joint. Was highly frustrating for editing trees or branches.
  In a next commit, there will be a different method to define IK target
  and IK root, so this option actually will become "Connect Bone" or so.

- the IK group name is gone, now is just an option "Tree IK". When IK
  chains share a root they'll form a tree.
  Todo is preventing conflicts here (will be for editor to define IK Root)

- Adding new IK constraint with CTRL+I activates Constraint

source/blender/include/BIF_editarmature.h

@@ -103,9 +103,6 @@ void	selectconnected_armature(void);
 void	selectconnected_posearmature(void);
 void	select_bone_by_name (struct bArmature *arm, char *name, int select);
 void    unique_editbone_name (char* name);
-void    attach_bone_to_parent(EditBone *bone);
-void    attach_bone_to_parent_cb(void *bonev, void *arg2_unused);
-
 
 void auto_align_armature(void);
 void create_vgroups_from_armature(Object *ob, Object *par);