Let's remove mootools.

There still might be some uses of it, but I'm not aware of anything
right now and it's better to break things earlier so that somebody
notices and it can be fixed.

scripts/compress-js

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-for file in `find js -name '*.js' -not -name '*min.js' -not -name 'mootools*'` ; do
+for file in `find js -name '*.js' -not -name '*min.js'` ; do
     mkdir -p sources/`dirname $file`
     mv $file sources/$file
     java -jar ./scripts/google-javascript-compiler/compiler.jar --js sources/$file --js_output_file $file --compilation_level ADVANCED_OPTIMIZATIONS