Cleanup & goodies for rigging geeks! :)

- PoseMode: Wkey menu, "Flip Left/Right Names". On selected bones, it flips
  the L/R tags in names, and calls the proper code to rename everything
  that's related (constraint targets, bone-childs, etc).
- PoseMode: Shift+S snapmenu: snap cursor to selected now works
- Outliner: select bones now correctly sets 'active' flag for bones,
  updating the UI as well.
  Also made sure you cannot select hidden bones in outliner.
- 3DWindow: in PoseMode/EditMode draws name of active Bone too (with user
  option "Draw active object name" set.
- Added the new Armature/PoseMode options in View3D pulldowns.

Cleanup:

- moved Pose code from editaction.c to poseobject.c
- removed BSE_editaction.h and BSE_editaction_types.h, moved contents of
  it to BIF_editaction.h. One include per C file should be fine. :)
  I know the src/ structure would require more elaborated includes, but
  we don't have that now...

source/blender/python/api2_2x/Bone.c

@@ -33,20 +33,26 @@ struct ScrArea; /*keep me up here */
 
 #include "Bone.h" /*This must come first */
 
-#include "BKE_main.h"
-#include "BKE_global.h"
-#include "BKE_armature.h"
-#include "BKE_action.h"
-#include "BKE_utildefines.h"
-#include "BLI_blenlib.h"
-#include "BLI_arithb.h"
-#include "BSE_editaction.h"
+#include "MEM_guardedalloc.h"
+
 #include "DNA_object_types.h"
 #include "DNA_ipo_types.h"
-#include "MEM_guardedalloc.h"
-#include "gen_utils.h"
+
+#include "BLI_blenlib.h"
+#include "BLI_arithb.h"
+
+#include "BKE_armature.h"
+#include "BKE_action.h"
+#include "BKE_global.h"
+#include "BKE_main.h"
+#include "BKE_utildefines.h"
+
+#include "BIF_editaction.h"
+
 #include "NLA.h"
 
+#include "gen_utils.h"
+
 //--------------------Python API function prototypes for the Bone module----
 static PyObject *M_Bone_New( PyObject * self, PyObject * args );