devdraw: OS X: neutralize menu and Dock bugs in fullscreen mode

Previously, the menu bar has been set to hidden
instead of autohidden in fullscreen mode, because
it appeared too easily.  Occasionally however, it
still appears.  This patch makes sure it won't.

With OS X Lion's fullscreen, the Dock is
autohidden, but sometimes remains hidden.  This
bug comes with visual menu bar bugs
during space transition and when exiting
fullscreen.  Those bugs happen after each
Devdraw's activation, for example.  This patch
neutralizes them.

R=rsc
CC=plan9port.codebot
http://codereview.appspot.com/5502091

src/cmd/devdraw/cocoa-screen.m

@@ -133,9 +133,6 @@ static NSCursor* makecursor(Cursor*);
 }
 - (void)windowDidBecomeKey:(id)arg
 {
-	if(win.isnfs || win.isofs)
-		hidebars(1);
-
 	in.touchevent = 0;
 
 	getmousepos();
@@ -685,6 +682,9 @@ getmousepos(void)
 	in.mpos.y = round(p.y);
 
 	updatecursor();
+
+	if(win.isnfs || win.isofs)
+		hidebars(1);
 }
 
 static void
@@ -1096,6 +1096,12 @@ hidebars(int set)
 	s0 = [[NSScreen screens] objectAtIndex:0];
 	old = [NSApp presentationOptions];
 
+#if OSX_VERSION >= 100700
+	/* This bit can get lost, resulting in dreadful bugs. */
+	if(win.isnfs)
+		old |= NSApplicationPresentationFullScreen;
+#endif
+
 	if(set && s==s0)
 		opt = (old & ~Autohiddenbars) | Hiddenbars;
 	else