In Render, colors shown were the default colors, not the selected colors, when starting Pcbnew or Gerbview,
because colors were not updated after reading the config.
* Fix grid select box update bug on context menu.
* Fix via size and track width select box update bugs.
* Fix layer pair indicator button update bug.
* Fix auto track width tool bar control enable bug.
* Fix via size and track width select status bug in context menu.
* Fix layer select box and layer control widget select bug when current
layer is removed.
* Add virtual function to notify objects derived from EDA_DRAW_FRAME that
the units setting has changed.
* Coding policy class naming fixes.
jean-pierre charras
Wayne Stambaugh
Dick Hollenbeck
charras