Rather than detaching and re-attaching the layer panels with the
attendant overhead, we keep each panel intact and only update its
contents. Since the bindings are the same, this saves substantial time
on pcb loading as well as when closing the board setup dialog
Also adds indicators in layers palette for feedback.
Also generates sized images for all indicators instead of using
scaled bitmaps (which didn't look great).
Also fixes a completely unrelated typo in a UI string.
The introduces INDICATOR_ICON, which is a very simple class holding a
bitmap that can toggle on or off.
The ICON_PROVIDER class then provides icons to INDICATOR_ICONS, which
means the class can be used for more than just row indicators.
A default row icon provider is also provided for use in the standard row
selector.
Seth Hillbrand
Ian McInerney
Wayne Stambaugh
Jeff Young
Chris Pavlina
jean-pierre charras
John Beard