
Add to port(1) the ability to query for specific meta-data fields.

This is added to the info action, by means of per-action options.

For instance:

	port info --maintainer --name category:java

When specific options are given, the legacy generalized info is not presented, and vis-versa.

By default, the fields for each port are listed one-per-line, with a field label
in front of each. (The field label is omitted if the global -q option is given).

	% port info --name --maintainer tomcat5 apache2
	maintainer: jberry@opendarwin.org
	name: tomcat5
	maintainer: james@imajes.info
	name: apache2

If the --line option is given, the fields are presented on one line, tab separated,
and with no field label.

	% port info --name --maintainer --line tomcat5 apache2
	jberry@opendarwin.org   tomcat5
	james@imajes.info       apache2

Note that the --line mode is particularly nice for later processing by sort, cut,
paste, etc.

Caveats:

-	Due to the way in which option processing is done, fields are always emitted
	in order alphabetically by field name. Sorry about that ;)

Other Notes:

-	Field names are those from the PortIndex, plus some convenience versions of
	those: (such as allowing category instead of categories).
-	Fields which are actually lists (such as depends_lib) are displayed comma-separated.

git-svn-id: 620571fa9b4bd0cbce9a0cf901e91ef896adbf27@16451 d073be05-634f-4543-b044-5fe20cf6d1d6

neverpanic/macports-base,macports/macports-base,macports/macports-base,danchr/macports-base,neverpanic/macports-base,danchr/macports-base