Closes #2391

The resolve callback allows the application code to modify the
resolved URL before it is normailzed by urlParsingNode.href for example:

var parsed = $urlUtils.resolve("foo", function(urlUtils) {
  urlUtils.protocol =
    urlUtils.protocol === 'https:' ? 'wss:' : 'ws:';
});
parsed.href // wss://localhost/foo

The resolved URL object now includes the aditional properties hostname,
port, pathname, hash and search.

Closes #3299

Conflicts:
	src/ng/compile.js
	src/ng/urlUtils.js

This feature allows resetting the timer on an ongoing `$timeout` promise.

A fourth optional argument is added to `$timeout` which is the
old promise to be reset.

I.e.: `promise = $timeout(fn, 2000, true, promise);`

This will call `fn()` 2 seconds after the last call to the `$timeout()`
function.