util: _detailedException to _exceptionWithHostPort

The _detailedException() helper function used to be local to the 'net'
module, but now that it has been moved to 'util' a more descriptive name
is desirable.

PR-URL: https://github.com/iojs/io.js/pull/250


Reviewed-By: Bert Belder <bertbelder@gmail.com>