prebuilt stock kernel

Change-Id: I57ac65e5fb206a72ad63bdd2217fbde414aa1345
updated 2nd-bootloader

Change-Id: I31c6599ab5d6d6f43c95a2dd0eba170842fa5a3a
recovery: update init.rc

Change-Id: I1efb8ce53acde43972d666122f4090ad7c8fc664
need bowser releasetools to support boot.img/recovery.img building

Change-Id: I6b59e5eed54fd572df3b3eab6bffda22e9407c02
update forbid_format

Change-Id: I438c2eaf27c5bb6b81859e12f4f829ef66d9b0ce
device cleanup

Change-Id: I0f5c1808b3eba00e3822bc994a33466265f03cf3