Issue #2970132 by neerajsingh, webflo: .ht.router.php causes a redirect loop when invoked from parent directory

Issue #1543858 by danquah, pp, alexpott, dawehner, cilefen, jmolivas, esod, jhedstrom, andypost, kenorb, bserem: Add a startup configuration for the built-in PHP server that supports clean URLs