Cleanup for r41713 PHP 4 warning page:

Cleanup for r41713 PHP 4 warning page:
* Avoid register_globals XSS vulns hitting the template directly
* Avoid register_globals XSS vulns when using funny URLs
* Avoid horrible links when using funny URLs :)
* Swapped REQUEST_URI for SCRIPT_NAME as primary in path check, since SCRIPT_NAME doesn't include the PATH_INFO bits so will work when hitting a URL like index.php/Foo/Bar, or hopefully a rewrite?
* Don't spew errors if the file_get_contents() fails
* Don't FATAL out if file_get_contents() doesn't exist -- new in 4.3.0 :)
* Add a link to PHP download page