* Fix about dialog escape key termination bug.
* Fix edit hot keys dialog escape key termination bug.
* Set schematic editor component properties dialog default button.
* Fix schematic editor plot DXF dialog escape key termination bug.
* Set PCB editor layers setup dialog default button.
* Set PCB editor swap layers dialog default button.
* Set PCB editor net list dialog default button.
* Add comment to UIPolicy.txt about escape key termination requiring proper
  dialog button IDs.