* Remove most (not all) variables that were initialized but never used that
cause GCC 4.6 to generate a warning.
* Fix bug in schematic library editor best zoom calculation.
* Make EDA_DRAW_FRAME current tool ID member variable private.
* Added global no tool selected ID to replace application specific no
tool selected IDs.
* Change SetToolID to prevent setting the tool ID to anything less than
the new global no tool selected ID and assert on debug builds.
* Change command and update user interface command event handlers to use
new global no tool selected ID.
* Fixed schematic library editor add pin hot key handler.
* 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.
Added: in file dialog, multiple file selection.
Added: Draw mode selector (in left toolbar):
Raw mode:
a Gerber image is drawn on screen without buffering.
Artifacts happen if there are negative items drawn, if more than one Gerber file is shown.
Stacked mode:
each Geber image is drawn in a buffer and after drawn on screen
No artifact with negative items.
Each Gerber image covers previous images.
OR mode (transparency mode):
each Geber image is drawn in a buffer and after drawn on screen
No artifact with negative items.
Each Gerber image is "ORed" with previous images, like in Pcbnew.
Try to optimize Draw function in buffered modes.
(Useful for PC that have problems with "blit" graphic function)
Fix minor issues.