CORS header trouble

[ThomasLocke]

Method DELETE is not allowed by Access-Control-Allow-Methods....

Verified to be a problem with calendar related calls.

ARGH!

[rostgaard]

Forgot to add issue ID to this commit 501db94
Reception server is now working CORS-wise.

[rostgaard]

I think all the servers that needs additional methods are patched up to use shelf instead of our implementation. One exception, however, would be the management server that needs general love. I think we will cross that road when we get to it, and just close this issue for now.