Rename BREW_FILE HOMEBREW_BREW_FILE

Because it's a global.h constant and that file can be included by other projects.

Library/Homebrew/global.rb

@@ -38,8 +38,8 @@ else
   HOMEBREW_CACHE=Pathname.new("~/Library/Caches/Homebrew").expand_path
 end
 
-HOMEBREW_PREFIX = Pathname.new(BREW_FILE).dirname.parent # Where we link under
-HOMEBREW_REPOSITORY = Pathname.new(BREW_FILE).realpath.dirname.parent # Where .git is found
+HOMEBREW_PREFIX = Pathname.new(HOMEBREW_BREW_FILE).dirname.parent # Where we link under
+HOMEBREW_REPOSITORY = Pathname.new(HOMEBREW_BREW_FILE).realpath.dirname.parent # Where .git is found
 
 # Where should be build to? 
 # If /usr/local/Cellar exists, as a symlink or real folder, use that.

Library/Homebrew/install.rb

 #!/usr/bin/ruby
-BREW_FILE = `which brew`.strip
+HOMEBREW_BREW_FILE = `which brew`.strip
 
 require 'global'
 

bin/brew

@@ -5,7 +5,7 @@
 # odd exceptions. Reduce our support burden by showing a user-friendly error.
 Dir.getwd rescue abort "The current working directory doesn't exist, cannot proceed."
 
-BREW_FILE = File.expand_path __FILE__
+HOMEBREW_BREW_FILE = File.expand_path __FILE__
 
 def homebrew_rubylib_path
   lib_path = "/../../Library/Homebrew"