Make local-tld optional on Mac OS X. Use dynamic ports everywhere.

`local-tld` can still be used if installed separately, but is no
longer a hard requirement.

This commit changes all local (i.e. not nodejitsu etc) port
allocations to the new `ports` module.
use single quotes consistently
Merge pull request #77 from hoodiehq/optional-local-tld

Make local-tld optional on Mac OS X. Use dynamic ports everywhere.