Redo the CORE_BRANCH idea into a STABILIZATION_BRANCH boolean

CORE_BRANCH never took off, so let's try going for permanent
stabilization branches instead...
REVERT ME LATER: Let stabilization branch builds use mainline device repos
Underp if[]
Fix exporting the fallback branches
Make room to build kitkat

Discontinue the separate workspaces for pre-jellybean versions,
since we're not building those anymore
use same branch as rest of project
Merge branch 'master' of git://github.com/CyanogenMod/hudson

Signed-off-by: David Rodero <david@codiguiel.net>

Conflicts:
	build.sh
	cm-build-targets