galaxy5: cm10.2 bringup & cleanup

* Update cm.dependencies and readme for CM10.2
* Remove all unnecessary config & code that belongs in shared config
* Revert to kernel 2.6 & ar6000 driver
* Fix building of libcamera
* Remove custom init.gt-i5500board.rc (shared init now compatible)
* Move custom hciattach & g5sensord services to init.parts.rc
* Update dalvik heap sizes (heapsize=32m, heapgrowlimit=24m,
  heaptargetutilization=0.25)
* Remove ro.vold.umsdirtyratio=20 (drastically slows UMS speed)
* Remove ALL LDPI overlay; anything that needs to be restored
  belongs in ldpi-common
* Use minimal font footprint (saves ~2MB)

Change-Id: Ie88626724563d0767ebeae957cf1650300049aeb