Fix a bug in the restamp-grub functionality, make sure we copy
the newer grub.cfg file, along with modules to each of the boot-environments.

This makes sure that the first BE (which grub loads by default) will
have the current modules / config.

Also, other BE's will have a current grub.cfg now, so when you boot
them, they will look as expected
Large update to the pc-updatemanager utility, this will add a new
method in which we do full system updates, along with package updates.

Background updating is now supported, by doing all the relevant pkg
changes in a mounted BE, then setting it to active before rebooting
into it.
Merge branch 'master' of github.com:pcbsd/pcbsd