Changed URI auto-detection to try PATH_INFO first

(thanks to @sourcejedi, PR #1326)

Up until PHP 5.2.4 (which is our new lowest requirement),
there was a bug related to PATH_INFO which made REQUEST_URI
a more reliable choice. This is now no longer the case,
see https://bugs.php.net/bug.php?id=31892 for more details.

Also removed ORIG_PATH_INFO from the suggested alternatives
for uri_protocol in application/config/config.php as it will
not exist in most of PHP's recent versions and is pointless
when you can use PATH_INFO anyway.
3 files changed