Revert "Switch to using the 'poudriere' branch while we testing using"

This reverts commit 2c764cedbd8930db7b650f174a2c12e9206f99c9.

This is not needed, we can go back to building the same ports in the freenas/9-stable
branch with poudriere, because the ports tree was fixed in #4839.
Revert "Comment out ports which have been removed from FreeBSD ports tree."

This reverts commit b8ac898287b592e18cd478dbf10c07de67a2fad2.

This is not needed, we can go back to building the same ports in the freenas/9-stable
branch with poudriere, because the ports tree was fixed in #4839.
Rename /d directory to .ports to make it easier to understand what it is used for.
Throttle poudriere to use 10 parallel builds.  This makes things a bit
more usable when multiple people are compiling on the same build server.
We can raise this limit later.