Disable NFS on OSX by default
Disable NFS on OSX by default

Three years ago we decided that the performance improvements offered by
NFS more than made up for the additional complexity that it added to the
system (4ee0463). After personally having several issues with the OSX
NFS server locking up randomly, I turned off NFS shares via `vagrant
config nfs_shares off` at least 18 months ago. We have a long list of
open and closed bugs that are related to NFS permissions issues or
problems on individual developer machines. After helping someone today
who seems to have run into
<https://github.com/mitchellh/vagrant/issues/8061>, I'm sick of it and
ready to undo the three year old decision that NFS is enough of
a performance improvement to warrant the additional complexity for the
average user.

This change leaves NFS shares as the default for Linux, BSD, FreeBSD,
and Solaris hosts. It also leaves the option for anyone to use `vagrant
config nfs_shares on` to enable NFS consciously for their local install.
I'm not disabling default support NFS (yet) for 'real' unix hosts in
part because I will need to figure out how to force NFS usage on
Wikimedia Labs hosts that are using MediaWiki-Vagrant and LXC. I know
from past testing that the native LXC sharing system does not work with
our setup due to file ownership issues.

Bug: T139859
Change-Id: I77099422d50c7eb7c6b64186497afe373a09eb76

wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant,wikimedia/mediawiki-vagrant