[web-php][PR #386] - Allow to access symlinked docs

You can view the Pull Request on github: https://github.com/php/web-php/pull/386 Opened By: cmb69 Pull Request Description: Since realpath() resolves links, symlinked docs as suggested by the "Setting up Documentation environment" page[1] are incompatible with the router script. Of course, the Webserver can be run without the router script, but in that case shortcuts (e.g. /json_decode) won't work. Thus, we remove the realpath() resolution. [1] <http://doc.php.net/tutorial/local-setup.php>