Add a shortcut to preview Markdown files
Revert "Remove a function to go to a GDS project."

This reverts commit 3030709925f4570240a12067c2003e0a95d94458.
Use GDS email address.
Add a command to SSH to the new dev VM.
Set the distribution environment variable.
Add directory for private scripts to $PATH.
Update default VM distro to Precise.
Use the `puppet/development` directory.

It's moved from just `development`.
Update `g` function to work on VMs too.
Add internal GitHub host to `hub`