Ensures lxc templates are executable prior to running `lxc-create`

Closes #128
Update Raring VBox dev VM
Add Saucy VBox dev VM
Improve logging and add some TODOs that have been around for a while
Dont think we need these examples anymore
Support rootfs param on generic lxc-template
Dont worry about machine state when waiting for communicator [GH-142] [GH-146]