Optimize JS with Google Closure Compiler.
Merge branch 'master' into gh-pages

The gh-pages branch will now serve as a demo of the latest "functioning" version of the project.  A new production branch will be created at a later date that will
incorporate performance optimizations such as minified/gzipped JavaScript, etc.
Something went wrong during the last merge.
Merge branch 'master' into gh-pages
Fix keypress responsiveness.