Leopard: Fix undefined method count for Array

Leopard runs Ruby 1.8.6 while Snow Leopard runs 1.8.7 and `Array.count` was not
introduced until 1.8.7.

Using `Array.length` instead.

Library/Homebrew/cmd/upgrade.rb

@@ -17,7 +17,7 @@ module Homebrew extend self
       ARGV.formulae.map{ |f| [f.prefix.parent, f.name, f.version] }
     end
 
-    if outdated.count > 1
+    if outdated.length > 1
       oh1 "Upgrading #{outdated.count} outdated package#{outdated.count.plural_s}, with result:"
       puts outdated.map{ |_, name, version| "#{name} #{version}" } * ", "
     end

Library/Homebrew/formula.rb

@@ -512,7 +512,7 @@ private
 
   def verify_download_integrity fn, *args
     require 'digest'
-    if args.count != 2
+    if args.length != 2
       type=CHECKSUM_TYPES.detect { |type| instance_variable_defined?("@#{type}") }
       type ||= :md5
       supplied=instance_variable_get("@#{type}")

Library/Homebrew/formula_installer.rb

@@ -176,7 +176,7 @@ class FormulaInstaller
   def check_PATH
     # warn the user if stuff was installed outside of their PATH
     [f.bin, f.sbin].each do |bin|
-      if bin.directory? and bin.children.count > 0
+      if bin.directory? and bin.children.length > 0
         bin = (HOMEBREW_PREFIX/bin.basename).realpath.to_s
         unless paths.include? bin
           opoo "#{bin} is not in your PATH"