FreeBSD: Change package name to .tbz and scan data dirs

* This commit changes the naming of the package. `pkg_add`
on FreeBSD needs package names to end in .tbz rather than .tgz
* The data and log directories were not scanned for extra
directories so some default directories would be left out
of the package install.
* Some directories such as /usr/sbin were included in the
default @dirrm list, those have been removed

Fixes: #77 #83
Merge pull request #84 from basho/jem-freebsd-package-fixes

FreeBSD: Change package name to .tbz and scan data dirs