LPS-52297 Handle OPTIONS request with NOT IMPLEMENTED HTTP Status code

Hi Ray,

Based on your feedback received by @laszlocsontos via e-mail, I've implemented the solution you mentioned with one modification. We discovered, that Sharepoint integration and WebDAV deals with OPTIONS requests, so I moved the URI checking from SharepointFilter to ServletRequestUtil and let the OPTIONS request go through InvokerFilter only when the URI matches the Sharepoint or WebDAV urls.

Please review my changes,

Regards,
Vilmos