Pull USERAGENT used by curl into constant

Library/Homebrew/formula.rb

@@ -174,10 +174,8 @@ private
       tgz=File.expand_path File.basename(@url)
     end
 
-    agent="Homebrew #{HOMEBREW_VERSION} (Ruby #{VERSION}; Mac OS X 10.5 Leopard)"
-
     unless File.exists? tgz
-      `curl -#LA "#{agent}" #{oarg} "#{@url}"`
+      `curl -#LA "#{HOMEBREW_USER_AGENT}" #{oarg} "#{@url}"`
       raise "Download failed" unless $? == 0
     else
       puts "File already downloaded and cached"

Library/Homebrew/unittest.rb

@@ -8,10 +8,10 @@ require 'utils'
 
 # these are defined in env.rb usually, but we don't want to break our actual
 # homebrew tree, and we do want to test everything :)
-HOMEBREW_VERSION='0.3t'
 HOMEBREW_PREFIX=Pathname.new '/tmp/testbrew/prefix'
 HOMEBREW_CACHE=HOMEBREW_PREFIX.parent+"cache"
 HOMEBREW_CELLAR=HOMEBREW_PREFIX.parent+"cellar"
+HOMEBREW_USER_AGENT="Homebrew"
 
 HOMEBREW_CELLAR.mkpath
 raise "HOMEBREW_CELLAR couldn't be created!" unless HOMEBREW_CELLAR.directory?

bin/brew

@@ -4,6 +4,7 @@ require 'env'
 require 'find'
 
 PRISTINE_ARGV=ARGV.dup
+HOMEBREW_USER_AGENT="Homebrew #{HOMEBREW_VERSION} (Ruby #{VERSION}; Mac OS X 10.5 Leopard)"
 
 # often causes Ruby to throw exception ffs
 Dir.chdir '/' unless File.directory? ENV['PWD']