Fixed nodejs detection in opentype.js by disable --dg of
browserify.

By default, browserify will add process shim in output javascript.
This will break our environment detection.

Also updated generated opentype.js and opentype.min.js.
ignore fs to prevent browserify to break fs module.
Merge pull request #63 from sunng87/master

Fixed nodejs environment errors caused by browserify.
Invalid CFF commands no longer throw an exception.

We found that some fonts, like Fira-Bold, have reserved CFF commands
embedded in them. (Maybe as a copy protection measure?) Instead
of throwing an error, we log the invalid command to the console.