Remove ability to build plugins from build system

- While we're here, remove jail build/package code that isn't used as
  well
Add graid5 back in (it snuck out during last commit)
Fix missing fi.
Fix permissions.
Rename GIT_FOO to GIT_FREEBSD_FOO to avoid confusion
Script to do checkouts and make a sandbox.
Cleanup: Remove traces of SVN/CVS and patches.
Refactor git checkouts.

Make use of the cache for initial checkout, but then switch
to using the real repo "github" to avoid confusion.

Consolodate src and ports into one function.
Fix the check for root before build.
Add module for truenas checkouts.
add 'checkout' to do_build.sh via '-c' to checkout sources.

This will allow and encourage us to checkout as non-root more easily.
support source checkout in top level Makefile
Fix some leftover PBI variables to work
allow user to specify freebsd/ports branch/repo/cache
comment out debug code
output extra newline before instructions
output sandbox vars for freebsd/ports branch
Packages for alternate NAS versions.
Auto-Commit of i18n data from Pootle for GUI
Suport for multiple ports repos.

We will use this for zfsd and other TrueNAS addons.

Conflicts:
	nanobsd/common