* Remove clearance and net class name read only text boxes from PCBNew
auxiliary tool bar.
* Display full net class information in message panel when an object that
supports net classes is selected.
* Move coordinate string conversion function to EDA_DRAW_FRAME object and
made it more versatile.
* Refresh message panel text when units change.
* 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.
* Old control state handling code completely removed in all applications.
* Factor common control state handlers into EDA_DRAW_FRAME.
* Replaced EDA_ITEM test for newness with IsNew() method.
* Factor vertical right toolbar command handlers out of giant edit command
switch statement in EESchema and PCBNew.
This was due to a duplicate constants ( with sligtly different values) used to select items in some seach functions that broke filtering. Old definitions removed.
Very minor enhancement in module edition dialogs.
Fix a minor bug in design rules editor: in Global Rules Edition: drill values > via diameter not checked
and the first item (track or via) in list was not checked (explains Bug 702177, that is not really a bug)