fix($location): consider baseHref in realtive link for legacy browsers

Request Type: bug
 
**How to reproduce:**

In a legacy browser that doesn't support HTML5 push state (ie: IE9) have the following:

- `$locationProvider.html5Mode(true).hashPrefix('!');` in app configuration;
- a number of routes such as `/foo`, `/bar` in the `$routeProvider` configuration;
- `<base href="/en/">` in page headers;
- `<a href="/en/foo">` in a link.

When clicking a link, it is rewritten as: `http://host/en/#!/en/foo` 
Expected: `http://host/en/#!/foo`

Component(s): $location

Impact: medium

Complexity: small

This issue is related to: 



**Other Comments:**

I couldn't yet devise any test for covering this case. This fix concern a click handler on the `$rootElement` which (afaik) is not covered in the current tests.

Please let me know if you find it reasonable and if you have ideas on how to test for it.
Thanks!
                     if (baseHref != '' && href.indexOf(baseHref) === 0) {
				href = href.substr(baseHref.length);
				if (!href || href[0] != '/') {
					href = '/' + href;
				}
			}