Don't require the WHOLE of Homebrew from ARGV.rb

This was slowing down every instantiation of brew significantly.

Hopefully doesn't break anything that had become accustomed to not having to require 'formula' or 'keg'.

/cc @mikemcquaid

Library/Homebrew/extend/ARGV.rb

@@ -1,5 +1,3 @@
-require 'bottles'
-
 module HomebrewArgvExtension
   def named
     @named ||= reject{|arg| arg[0..0] == '-'}
@@ -115,10 +113,12 @@ module HomebrewArgvExtension
   end
 
   def build_bottle?
+    require 'bottles'
     bottles_supported? and include? '--build-bottle'
   end
 
   def build_from_source?
+    require 'bottles'
     flag? '--build-from-source' or ENV['HOMEBREW_BUILD_FROM_SOURCE'] \
       or not bottles_supported? or not options_only.empty?
   end