Reworked LogStorage to avoid unnecessary extra calls to write().

Bugs closed: AURORA-134

Reviewed at https://reviews.apache.org/r/18241/
AURORA-225: Shell scripts in checkout should use an absolute path

Testing Done:
Submitted this review with the following command:
 ../rbt post -o -g (from inside of build-support directory)

Bugs closed: AURORA-225

Reviewed at https://reviews.apache.org/r/18345/