revert fix($location): make legacy browsers behave like modern ones in html5Mode

These commits have caused more problems than they've been worth, and we get to remove some code, too.

Reverts: https://github.com/angular/angular.js/commit/3f047704c70a957596371fec554d3e1fb066a29d, https://github.com/angular/angular.js/commit/49e7c32bb45ce3984df6768ba7b2f6a723a4ebe7

Opinions on reverting these would be appreciated! /cc @IgorMinar