[CHEF-4973] Fix Freebsd vagrant box naming convention

This commit includes

* Fixes for Vagrant bug in <1.5 with shared folders
* Updates to URL for Dyn backed Freebsd boxes
* Update default 8.3 and 9.1 boxes for chef 11.8.0
[CHEF-4973] Remove vagrant monkeypatch and update platform name for FreeBSD

Remove unnecessary comment
Merge pull request #114 from petecheslock/master

[CHEF-4973] Fix Freebsd vagrant box naming convention