Fix exporting the unique build identifier

Change-Id: Ie58e981b7e83a4351d137dfd8995dce7d365d950

Conflicts:
	envsetup.sh
Merge "inline kernel dtb build" into cm-10.2
build: Prevent some auto-generated variables from being overridden

These variables are used by internal processes for build indexing
and identification, and those processes expect either specific patterns,
or uniqueness.
So prevent accidental overriding of these by device configurations:
BUILD_DISPLAY_ID, BUILD_NUMBER, PLATFORM_VERSION, PLATFORM_SDK_VERSION,
PLATFORM_VERSION_CODENAME, BUILD_VERSION_TAGS

Change-Id: I06252f2687a5e5fd97ee21a98f26c739fd0ef6e4
Fix incremental build number on Darwin

Darwin does not include sha1sum, but it should have openssl.

Change-Id: If2b685c1478f9486bed21dfba0c655d9e02db72b

Conflicts:
	envsetup.sh
repopick: skip a cherry pick if its already been merged

* override this behavior with the -f argument

Change-Id: I280b4945344e7483a192d1c9769c42b8fd2a2aef