Fix #769: String.prototype.normalize breaks reflected attributes.

This is especially a problem in Node v0.11.13, where String.prototype.normalize is added by default, and throws a RangeError if called with invalid arguments.
Lazily load the request module.

When not downloading from the internet, it is not needed; delaying loading it until then speeds up jsdom execution by 30-50%.
Fix for passing a whitepsace string to jsdom.jsdom()

Fixes a bug where calling jsdom.jsdom(' ') resulted in a document with
no html, while jsdom.jsdom('') resulted in the default <html>...</html>
Add remaining URL attributes

origin, password, username, and search to <a> element; origin to window.location.
Fixes iframe load handling when src empty/unspecified
Clean up initInsertListener
Update spec references to reflect living standards.

We've been moving this way for a while; it's time to acknowledge the updated situation.
Version 0.10.6
Whoops, missed a spec reference update.
Fix syntax by adding missing parenthesis.
Merge branch 'master' of https://github.com/tmpvar/jsdom
Added new level 'living'. Fixed DocumentType.parentNode