wow this has been double derped

Cheers aaron :)
Merge pull request #7 from tonyp/patch-2

wow this has been double derped
Split to multiple bash commands.

This can fix the error "/bin/bash: Argument list too long", if we get a
really long apk list.
Bug tracker Link: http://code.google.com/p/android/issues/detail?id=38937

Change-Id: I72258125c4297dfd9f8f502a96dbfa5a08f3cc50
Allow override of device asserts, including multi-device support.

Set in board file with TARGET_OTA_ASSERT_DEVICE.
(cherry-picked from commit 0f452f2)

Change-Id: I3d06bdc0e3e26bde0c0e646accd050364f9713b9
add no_assets.option
Change-Id: I489e7b965aa2e4286ebacd64006522a5d206f2db