==Sequencer==

Added patch by Matt Ebb, that enhances the sequencer GUI in several ways:
- It looks a lot better
- Strip colours are themeable.
- The drawing code is more readable.
- The background of the timeline makes now distinguishing the channels easier
  by alternating between different shades of gray.
- Handle-scaling is clamped to min and max-values, making it possible to
  grab strips at large zooming levels more easily.
- Preview-images can be panned by dragging it with the middle mouse button.
  Home-Key resets the position.
- Since some people can't grab the meaning of "C 0", it is renamed to "Chan: 0"
- Effect strips have slightly different colors to distinguish them better.

Additionally:
- fixed an off by one error in Matt's patch
- Scene-rendering saves CFRA to avoid jumping current-scene on scrub
  (might be academic fix, since most likely it only happens if you add
  the sequencer-scene to the timeline... But nevertheless it bugs you on
  testing the GUI ;-)

source/blender/src/sequence.c

@@ -887,6 +887,7 @@ static void do_build_seq_ibuf(Sequence * seq, int cfra)
 				}
 			}
 			else if(seq->type==SEQ_SCENE && se->ibuf==0 && seq->scene) {	// scene can be NULL after deletions
+				int oldcfra = CFRA;
 				Scene *sce= seq->scene, *oldsce= G.scene;
 				Render *re= RE_NewRender(sce->id.name);
 				RenderResult rres;
@@ -918,6 +919,7 @@ static void do_build_seq_ibuf(Sequence * seq, int cfra)
 				
 				if((G.f & G_PLAYANIM)==0) /* bad, is set on do_render_seq */
 					waitcursor(0);
+				CFRA = oldcfra;
 			}
 			
 			/* size test */