Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

META MODE: These need object directories to handle staging.

Sponsored by: EMC / Isilon Storage Division

META_MODE: Remove DEP_RELDIR from Makefile.depend files.

This has not been needed since r284171 in projects/bmake.

Sponsored by: EMC / Isilon Storage Division

Add META_MODE support.

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

Follow-up to r255036; remove beforeinstall directives from bsdconfig(8)
Makefile's, fixing concurrent installworld (`make -j17 installworld').

Thanks to: delphij, emaste
Reviewed by: delphij
MFC after: 3 days
X-MFC-to: stable/10, stable/9

Commit first portion of package module -- this includes the ability to view
categories, view packages, mark packages for installation, de-installation,
or re-installation, calculate and track dependencies, as well as ability to
review selections.

Still to come is the actual processing of selections (performing the
various actions associated with the user's selections, such as installing
dependencies first, then selections, etc.).