Fix up the compilation process

Rakefile

@@ -6,10 +6,60 @@ file "lib/handlebars/parser.js" => "src/handlebars.yy" do
   sh "mv handlebars.js lib/handlebars/parser.js"
 end
 
-task :build => "lib/handlebars/parser.js"
+task :compile => "lib/handlebars/parser.js"
 
-task :test => :build do
+desc "run the spec suite"
+task :spec => [:release] do
   system "rspec -cfs spec"
 end
 
-task :default => [:build, :test]
+task :default => [:compile, :test]
+
+def remove_exports(string)
+  match = string.match(%r{^// BEGIN\(BROWSER\)\n(.*)\n^// END\(BROWSER\)}m)
+  match ? match[1] : string
+end
+
+minimal_deps = %w(ast jison_ext handlebars_lexer parser runtime utils).map do |file|
+  "lib/handlebars/#{file}.js"
+end
+
+debug_deps = %w(ast jison_ext handlebars_lexer printer parser runtime utils).map do |file|
+  "lib/handlebars/#{file}.js"
+end
+
+minimal_deps << "lib/handlebars.js"
+debug_deps   << "lib/handlebars.js" << "lib/handlebars/debug.js"
+
+minimal_deps.unshift "dist"
+debug_deps.unshift   "dist"
+
+def build_for_task(task)
+  FileUtils.rm_rf("dist")
+  FileUtils.mkdir_p("dist")
+
+  contents = ["var Handlebars = {};"]
+  task.prerequisites.each do |filename|
+    next if filename == "dist"
+
+    contents << "// #{filename}\n" + remove_exports(File.read(filename)) + ";"
+  end
+
+  File.open(task.name, "w") do |file|
+    file.puts contents.join("\n")
+  end
+end
+
+file "dist/handlebars.js" => minimal_deps do |task|
+  build_for_task(task)
+end
+
+file "dist/handlebars.debug.js" => debug_deps do |task|
+  build_for_task(task)
+end
+
+task :build => [:compile, "dist/handlebars.js"]
+task :debug => [:compile, "dist/handlebars.debug.js"]
+
+desc "build the build and debug versions of handlebars"
+task :release => [:build, :debug]