Avoid flickering on frame creation with tool bar on OSX.

* nsmenu.m (update_frame_tool_bar): Return early if view or toolbar
is nil.  If waiting for toolbar to complete, force a redraw.

* nsterm.h (EmacsView): Add wait_for_tool_bar.

* nsterm.m (updateFrameSize:): If waiting for the tool bar and tool
bar is zero height, just return.
(initFrameFromEmacs:): Initialize wait_for_tool_bar.

Conflicts:
	src/ChangeLog
* nsmenu.m (free_frame_tool_bar): Set wait_for_tool_bar = NO

Conflicts:
	src/ChangeLog