Use UJS to wrap code in a closure to prevent __extends from leaking out.

- Now all the "var libjass;" statements are stripped, as opposed to all but the first.
- All but the first "var __extends = ..." are now stripped. Consequently, it doesn't need to check for this.__extends either.
- Minification step now generates a warning about being unable to figure out a source mapping but it appears to be harmless.
Use UJS to align multi-line comments properly and strip TypeScript reference comments.
Removed the use of eval to get the global this-object.