Added '--installed' option to deps command.

When deps command is passed this option, it will only show the dependencies
for the installed forumas. This option overrides the '--all' option.

Closes Homebrew/homebrew#18276.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

Library/Contributions/manpages/brew.1.md

@@ -78,7 +78,7 @@ Note that these flags should only appear after a command.
     The options `--set-name` and `--set-version` each take an argument and allow
     you to explicitly set the name and version of the package you are creating.
 
-  * `deps [--1] [-n] [--tree] [--all]` <formula>:
+  * `deps [--1] [-n] [--tree] [--all] [--installed]` <formula>:
     Show <formula>'s dependencies.
 
     If `--1` is passed, only show dependencies one level down, instead of

Library/Homebrew/cmd/deps.rb

@@ -9,7 +9,11 @@ end
 
 module Homebrew extend self
   def deps
-    if ARGV.include? '--all'
+    if ARGV.include? '--installed'
+        Formula.installed.each do |f|
+          puts "#{f.name}: #{f.deps*' '}"
+        end
+    elsif ARGV.include? '--all'
       Formula.each do |f|
         puts "#{f.name}: #{f.deps*' '}"
       end

share/man/man1/brew.1

@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "BREW" "1" "February 2013" "Homebrew" "brew"
+.TH "BREW" "1" "March 2013" "Homebrew" "brew"
 .
 .SH "NAME"
 \fBbrew\fR \- The missing package manager for OS X
@@ -84,7 +84,7 @@ If \fB\-\-no\-fetch\fR is passed, Homebrew will not download \fIURL\fR to the ca
 The options \fB\-\-set\-name\fR and \fB\-\-set\-version\fR each take an argument and allow you to explicitly set the name and version of the package you are creating\.
 .
 .TP
-\fBdeps [\-\-1] [\-n] [\-\-tree] [\-\-all]\fR \fIformula\fR
+\fBdeps [\-\-1] [\-n] [\-\-tree] [\-\-all] [\-\-installed]\fR \fIformula\fR
 Show \fIformula\fR\'s dependencies\.
 .
 .IP