Build - Stop installing the sample APN list

* Sample APN list is always being installed, we don't want this in CM.

Change-Id: Ie29efec9baf9b0da4e56a5e53ae566ce97679ae4
Signed-off-by: STELIX <ssspinni@gmail.com>
Build - env: implement the repodiff command

sample usage:
   repodiff ics
   repodiff github/ics --numstat
   repodiff android-4.0.4_r1.2 android-4.0.4_r2

Change-Id: Iffa625e640ce0174ca6bfeeee069624c789afeba
Signed-off-by: STELIX <ssspinni@gmail.com>