There has been some fallout from the change. The change itself was not valueable
enough to spend time investigating the corner cases, let's just back it out.
Reported by: flo
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.
Still need to add real targets under targets/ to build packages.
Differential Revision: D2796
Reviewed by: brooks imp
