cooja TimeLine: double-click too short

250ms is too short an interval to use as a default.  In lieu of making this
configurable or obeying window system overrides, use Windows default 500ms
as the maximum interval.

Closes: pabigot/contikix#1
Signed-off-by: Peter A. Bigot <pab@pabigot.com>
cooja RadioLogger: fix misleading column names

"From" and "To" suggest these columns provide the source and destination
nodes of the packet.  They do not; they identify the node that transmitted
the packet and up to two nodes that received it, which are in no way the
same thing as the requested source and destination.  This is particularly
misleading when dealing with broadcast packets.  Rename the columns "TX" and
"RX" respectively.

Closes: pabigot/contikix#3
Signed-off-by: Peter A. Bigot <pab@pabigot.com>
cooja TimeLine: refactor zoom infrastructure

Refactor common code into private functions.  Abstract to support zoom
to level or exact value, with or without range filtering.

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.

Reference: http://forums.oracle.com/thread/1356291
Closes: pabigot/contikix#2
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 fix pabigot/contikix#4.

Closes: pabigot/contikix#5
Signed-off-by: Peter A. Bigot <pab@pabigot.com>