add support for user:password syntax in urls to get_url
minor doc changes
Update library/ec2

I've uncommented and added a very little supporting stuff based on skvidal's work to allow us to launch more than one instance.
Update library/ec2

bumping up min_count value.
Added hg module to the core.
Update library/ec2

updated indentation and redundant comment.
Standardize the hg command execution around our run command function.