added initial skeleton for automatically uploading ~/.ssh/id_rsa.pub to GCE
checking to see if our ssh key is in the GCE metadata
creating ssh key in GCE if it is not already there
Merge remote-tracking branch 'origin' into autoupload-ssh-keys
refactored GCEAgent to generate a new ssh keypair, instead of using the one in id_rsa (as it may require a passphrase to unlock)
Merge pull request #251 from shatterednirvana/autoupload-ssh-keys

Create SSH keys for users in GCE, instead of forcing them to do it