info: decorate deps to show installed status?

* shows green tick if installed or red cross if not
* only highlight dependency if HOMEBREW_NO_EMOJI is set

Closes Homebrew/homebrew#18922.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Homebrew/cmd/info.rb

@@ -122,7 +122,7 @@ module Homebrew extend self
       ohai "Dependencies"
       %w{build required recommended optional}.map do |type|
         deps = f.deps.send(type)
-        puts "#{type.capitalize}: #{deps*', '}" unless deps.empty?
+        puts "#{type.capitalize}: #{decorate_dependencies deps}" unless deps.empty?
       end
     end
 
@@ -136,6 +136,21 @@ module Homebrew extend self
     ohai 'Caveats', c.caveats unless c.empty?
   end
 
+  def decorate_dependencies dependencies
+    # necessary for 1.8.7 unicode handling since many installs are on 1.8.7
+    tick = Tty.green + ["2714".hex].pack("U*") + Tty.reset
+    cross = Tty.red  + ["2718".hex].pack("U*") + Tty.reset
+
+    deps_status = dependencies.collect do |dep|
+      if ENV['HOMEBREW_NO_EMOJI']
+        "%s%s%s" % [(dep.installed? ? Tty.green : Tty.red), dep, Tty.reset]
+      else
+        "%s %s" % [dep, (dep.installed? ? tick : cross)]
+      end
+    end
+    deps_status * ", "
+  end
+
   private
 
   def valid_url u