build: Add optional target-specific bootclass jar to dexpreopt

Allow target-specific additional boot class jars via
TARGET_ADDITIONAL_BOOTCLASSPATH for dexpreopt.

Change-Id: I67b31628bc8169f8df09e836b79618aa2a22ed9a
envsetup: fix 'eat' command

Change-Id: I5990dc49a72f1217ec0ca1c9e605b449e04403b4
Signed-off-by: Roman Birg <romanbirg@gmail.com>
Merge "build: Add optional target-specific bootclass jar to dexpreopt" into jb-mr2
Merge "envsetup: fix 'eat' command" into jb-mr2
Merge branch 'jb-mr2' of https://github.com/AOKP/build into jb-mr2