Improve intelligence of keyboard accelerator handling #53
Description
The hotkey accelerators are not completely working. As an example take the Axis Position Forward and Axis Position Backward plugins. Their hotkeys are defined as GREATER and LESS but on U.S. keyboards those are actually shifted keys (shift PERIOD and shift COMMA) which the AcceleratorHandler cannot handle.
This issue also affects the zoom commands (PLUS is really shift EQUALS on U.S. keyboards), and potentially any user commands that use affected keys, as well as any users using a non-U.S. keyboard layout.
We should improve the AcceleratorHandler to somehow recognize when two key codes are equivalent with respect to the active keyboard layout.
Migrated-From: http://trac.imagej.net/ticket/625