- added ^T to toggle terrain-follow
- added M and m to decrease and increase warp
- added p to pause and unpause the sim
- added T and t to decrease and increase warp delta
- added X and x to increase and decrease field of view
- added Z and z to decrease and increase visibility
- added F2 to force a tile-cache update
- added F4 to force a lighting update
- added F9 to toggle textured rendering
- new external file for joystick configuration
- designed for a basic three-axis, three-button joystick; others will
require some work
** keyboard.xml
- changed back to using index ('n' attribute) to represent key code
- switched to nesting for modifiers, so that they can all appear in
the same declaration
- bound 'b' to brake, but modified so that the brake is released
as soon as the button is
** preferences.xml
- start mixture at 1.0 (full rich), which is most appropriate for
take-off and landing
- commented out old joystick bindings
- added reference to external joysticks.xml file
