Major cleanup of JS sample code.

[slightlyoff]

Update of PR #17.

Move to a more modern JS style for the Tracer JS example. Includes:

• Strict mode conformance
• Use methods instead of prototype de-ref indirections
• Better use of Object.create() in subclasses
• Better defaults in the web example page
• Updates previous PR to remove ToNumber()'s in math methods.

[mraleph]

I think overall it looks good to me.

@johnmccutchan could you also take a look?

[slightlyoff]

Done.