Remove config.ssh.timeout due to backward incompatibility with Vagrant 1.3.0

Vagrant 1.3.0 eliminated some configuration options, config.ssh.timeout being one of them.

Not going to replace with anything at the moment, we'll see if there is a need to set the general vm timeout at a later time.
Adjust drive mounting options for Vagrant 1.3.0 compatibility

Vagrant 1.3.0 no longer supports the `:extra` flag and uses `:mount_options` with an array of values instead.
Use Vagrant 1.3.0