use mod_rewrite to pretend theese files are not existend for security purposes

That file was accidentally commited. Partially revert https://github.com/owncloud/core/commit/f2fc214ce0455ce9a9def36bd09285e82b5eabec

This functions are deprecated and/or removed since ownCloud 7. Additionally a issubdirectory check has been added here to prevent developers to use this function in a potentially insecure way.

Port of https://github.com/owncloud/core/pull/9033

The getfile routing code was absolutely legacy and not needed anymore. Additionally \OC::$REQUESTEDAPP was never set to the actually accessed application.

This commit removes the legacy routing code and ensures that $REQUESTEDAPP is always set so that other applications (e.g. the firewall or a two-factor authentication) can intercept the currently accessed app.

Testplan:
[x] Installation works
[x] Login with DB works
[x] Logout works
[x] Login with alternate backend works (tested with user_webdavauth)
[x] Other apps are accessible
[x] Redirect on login works (e.g. index.php?redirect_url=%2Fcore%2Findex.php%2Fsettings%2Fapps%3Finstalled)
[x] Personal settings are accessible
[x] Admin settings are accessible
[x] Sharing files works
[x] DAV works
[x] OC::$REQUESTEDAPP contains the requested application and can be intercepted by other applications

1. We're maintaining the same code twice which leads inevitably to problems as this one. The createHtaccess routine is only used to use the correct paths to the 404 and 403 document.
2. Updating the ownCloud instance as described in our documentation (`Delete everything from your ownCloud installation directory, except data and config.`) will break the links to the ErrorDocuments anyways and show the default error handlers if ownCloud is not installed in the root directory.

Add JS redirect if that fails (HTTP-based redirects are disabled by
default in more recent Firefox versions).

php_value can only be used with mod_php, using it with FCGI will cause 500 Internal Server errors.  This needs to be set in php.ini manually or set using ini_set().

This reverts commit e1478117.

add caldav and carddav files in their old place for backward compatibility - add rewriterule for caldav and carddav

Fixes:
http://bugs.owncloud.org/thebuggenie/owncloud/issues/oc-232
http://bugs.owncloud.org/thebuggenie/owncloud/issues/oc-445