cooja TimeLine: refactor zoom infrastructure

Refactor common code into private functions.  Abstract to support zoom
to level or exact value.

There should be no behavioral change as a result of this patch except:

 * zooms are consistently filtered to be in the valid range (those from
   configuration parameters formerly had been used directly);
 * the correct centerTime is used for zoomOutAction when
   mousePixelPositionX is positive

Supports pabigot/contikix#5

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
cooja TimeLine: zoom keystroke failure

The + typed character can only be generated on English keyboards by
shift-equals, resulting in a failure to recognize ctrl-plus because of
the unexpected shift modifier.  Adapt by supporting English and Spanish
keyboards, as well as number pad keys.

Closes pabigot/contikix#2

Reference: http://forums.oracle.com/thread/1356291
Signed-off-by: Peter A. Bigot <pab@pabigot.com>
cooja TimeLine: support mouse wheel zoom

Add listener that zooms based on mouse wheel.  The zoom center is the
mouse position, which alleviates the pressure to touch pabigot/contikix#4.

Closes pabigot/contikix#5

Signed-off-by: Peter A. Bigot <pab@pabigot.com>
Merge pull request #271 from pabigot/push/cooja-zoom

Push/cooja zoom
Removed some more old RCS tags from the Contiki source tree.
Merge pull request #273 from oliverschmidt/master

Removed some more old RCS tags from the Contiki source tree.
Made use of Atari XL shadow RAM.

The new Atari XL target allows cc65 programs to make use of
the shadow RAM. This allows to turn aon all features of the
web browser - and will allow for additional improvements to
come :-)
Merge pull request #274 from oliverschmidt/master

Made use of Atari XL shadow RAM.
Merge remote-tracking branch 'upstream/master'