remove "wipe battery stats" function prototype

Change-Id: I4d1589b68359c0a301fcf9fc2a1d58c7953d5938
Fix use of TARGET_USE_CUSTOM_LUN_FILE_PATH

TARGET_USE_CUSTOM_LUN_FILE_PATH is already available as a
string to extendedcommands.c, regardless of whether it is
quoted or unquoted in BoardConfig.mk.  Removed STRINGIFY define
because it is already available in common.h (along with EXPAND
which shoud be used instead of STRINGIFY anyways).

This was Fixed In CM10.1 but Most devices dont have cm10.1
for now.

This Fix is From Matt Mower

Change-Id: Ib7f16856fcefcc9a9f68383e6dc67cfbd3da1898
Merge "remove "wipe battery stats" function prototype" into jellybean