Added a few more non-standard tests

* Date.prototype.toLocaleFormat
* error "columnNumber"
* `__lookupGetter__`

Also updated the `toSource` test a bit.
Added more non-standard tests, 2

* String generics
* for each...in
* Iterator
* __iterator__

Also fixed Error#columnNumber and String#replace flags support values.
Added non-standard array/generator c12s

c12s = comprehensions.
Added non-standard old-style generator test

This tests for generators that use the JS 1.8 syntax - no asterisk by
the function keyword, and .next() returns an unwrapped value.
Cleanup + added more links

Removed some accidental console.log lines (groan), addressed a few
consistency/readability issues with the tests, and added more MDN links
for various tests.

I considered loosening some of the checks on the toSource method test
(such as avoid testing less useful methods like Number#toSource or
Error#toSource), but decided to leave it for now.
Merge pull request #218 from webbedspace/spidermonkey-extensions

Added more non-standard tests