releasetools: Allow to build with a separate output directory

Change-Id: I5898d64108fa5f9b6ea8cee2c401dfdff47f17a2
releasetools: Follow build system changes

http://review.cyanogenmod.org/#/c/58533/

Change-Id: I786ece076d50b3ac4fff8833523e1174b5c005a5
otter2: Trying to fix up reboot into recovery

Some users claimed it never worked, end up with the tablet shutdown instead of
reboot into recovery.

Change-Id: I14a407c476d88177b433551d0aee7939496e8da6