Merge remote-tracking branch 'discourse/master'
Fix guard warning with version spec for rb-notify.
Increase timeout for spork startup.
Fix Guardfile warning about deprecated :version arg.
Tuneups of Vagrant

Increase memory allocation to 512MB so guest VM is not swapping.
SSH forwarding, DNS host nat resolver.
Don't use NFS on darwin, just use standard folder sharing.
Update & simplify vagrant instructions.

The gem installer is deprecated, direct people to the real installer.
No longer need to require XCode and RVM installs, just install vagrant
and go. Password prompt during boot only happens on windows, not OS X
and Linux hosts.
Merge pull request #54 from patdeegan/test-cleanups

Test cleanups.