dzen2: Modify dzen-extras, update Makefile and recipe.

dzen2: Modify dzen-extras, update Makefile and recipe.

Modularized the battery applet by moving the charge calculation
in an external script and adding per-platform functions. Made the
process a bit more efficient by adding a small program written in
C, dzen-battery, which calculates a battery percentage given two
standard files in /sys/class/power_supply and by moving processes
outside the main loop when they only need to run once.

Modified Makefile for dzen-battery.c

Bumped PR on dzen2-svn

Signed-off-by: Alex Ferguson <thoughtmonster@gmail.com>
Signed-off-by: Kristoffer Ericson <kristoffer.ericson@gmail.com>