UI:

* For new buttons spaces, automatically set horizontal/vertical
  align depending on size, instead of free.

* Cleaned up the UI panel API. There's now a new uiBeginPanel
  function which takes a panel type, and a uiEndPanel which takes
  the final size. uiNewPanel* functions will be phased out.
* Animate the re-alignment when a panel size changes, e.g. when
  enabling dupliframes.

* Load ui scripts from the release/ folder first if it is
  available. This makes it easier to edit ui scripts, since it
  will directly use the original files which avoids having to
  run the build system.
* Improve editing of panel types while blender is open. That
  means fixing some issues with lacking updates, overlaps, strange
  ordering. It even does an animation now when the panel resizes.

source/blender/editors/include/UI_interface.h

@@ -481,18 +481,18 @@ void autocomplete_end(AutoComplete *autocpl, char *autoname);
  * could use a good cleanup, though how they will function in 2.5 is
  * not clear yet so we postpone that. */
 
-extern void uiNewPanelTabbed(char *, char *);
+void uiBeginPanels(const struct bContext *C, struct ARegion *ar);
+void uiEndPanels(const struct bContext *C, struct ARegion *ar);
+
+struct Panel *uiBeginPanel(struct ARegion *ar, uiBlock *block, struct PanelType *pt);
+void uiEndPanel(uiBlock *block, int width, int height);
+
+void uiPanelsHome(struct ARegion *ar);
+
+/* deprecated */
 extern int uiNewPanel(const struct bContext *C, struct ARegion *ar, uiBlock *block, char *panelname, char *tabname, int ofsx, int ofsy, int sizex, int sizey);
-
-extern void uiBeginPanels(const struct bContext *C, struct ARegion *ar);
-extern void uiEndPanels(const struct bContext *C, struct ARegion *ar);
-extern void uiFreePanels(struct ListBase *lb);
-	
-extern void uiPanelsHome(struct ARegion *ar);
-
 extern void uiNewPanelHeight(struct uiBlock *block, int sizey);
 extern void uiNewPanelTitle(struct uiBlock *block, char *str);
-struct Panel *uiPanelFromBlock(struct uiBlock *block);
 
 /* Handlers
  *