Add Jack submodule to External

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "External/ojunit"]
 	path = External/ojunit
 	url = git://github.com/280north/ojunit.git
+[submodule "External/jack"]
+	path = External/jack
+	url = git://github.com/tlrobinson/jack.git

External/Rakefile

@@ -9,6 +9,7 @@ require 'fileutils'
 
 $ENVIRONMENT_NARWHAL_PRODUCT = File.join($ENVIRONMENT_DIR, 'narwhal')
 $ENVIRONMENT_BROWSERJS_PRODUCT = File.join($ENVIRONMENT_NARWHAL_PRODUCT, 'packages', 'browser')
+$ENVIRONMENT_JACK_PRODUCT = File.join($ENVIRONMENT_NARWHAL_PRODUCT, 'packages', 'jack')
 
 $ENVIRONMENT_NARWHAL_EXECUTABLE = File.join($ENVIRONMENT_BIN_DIR, 'narwhal')
 
@@ -24,6 +25,10 @@ file_d $ENVIRONMENT_BROWSERJS_PRODUCT => [$ENVIRONMENT_NARWHAL_PRODUCT] do
     cp_r('browser.js', $ENVIRONMENT_BROWSERJS_PRODUCT)
 end
 
-task :build => [$ENVIRONMENT_NARWHAL_PRODUCT, $ENVIRONMENT_BROWSERJS_PRODUCT, $ENVIRONMENT_NARWHAL_EXECUTABLE]
+file_d $ENVIRONMENT_JACK_PRODUCT => [$ENVIRONMENT_NARWHAL_PRODUCT] do
+    cp_r('jack', $ENVIRONMENT_JACK_PRODUCT)
+end
 
-CLOBBER.include($ENVIRONMENT_NARWHAL_PRODUCT, $ENVIRONMENT_BROWSERJS_PRODUCT, $ENVIRONMENT_NARWHAL_EXECUTABLE)
+task :build => [$ENVIRONMENT_NARWHAL_PRODUCT, $ENVIRONMENT_BROWSERJS_PRODUCT, $ENVIRONMENT_JACK_PRODUCT, $ENVIRONMENT_NARWHAL_EXECUTABLE]
+
+CLOBBER.include($ENVIRONMENT_NARWHAL_PRODUCT, $ENVIRONMENT_BROWSERJS_PRODUCT, $ENVIRONMENT_JACK_PRODUCT, $ENVIRONMENT_NARWHAL_EXECUTABLE)