GitHub usernames in maintainers field

[Joshua Root]

MacPorts 2.3.5 added the ability to list GitHub usernames as well as 
email addresses in the maintainers field of Portfiles. Basically instead 
of this:

maintainers	jmr openmaintainer

you can do this:

maintainers	{jmr @jmroot} openmaintainer

All the email obfuscation etc still works the same way, you just wrap 
each email and GitHub username that correspond to the same person in 
braces together.

Documentation of this should hopefully be added to the Guide soon. I 
would encourage port maintainers to add their GitHub username to their 
ports.

A couple more examples:

maintainers	{jmr @jmroot} {raimue @raimue}

maintainers	{jmr @jmroot} {example.com:user @example} openmaintainer

- Josh