[MODCLUSTER-410] registered MCMP methods with httpd

fixed **OPTIONS** method so now **Allow** header is returning all of the MCMP methods. 

#### sample **OPTIONS** output:

````bash
$ curl -X OPTIONS http://127.0.0.1:6666

* About to connect() to 127.0.0.1 port 6666 (#0)
*   Trying 127.0.0.1...
* Adding handle: conn: 0x7f8353003a00
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0x7f8353003a00) send_pipe: 1, recv_pipe: 0
* Connected to 127.0.0.1 (127.0.0.1) port 6666 (#0)
> OPTIONS / HTTP/1.1
> User-Agent: curl/7.30.0
> Host: 127.0.0.1:6666
> Accept: */*
> 
< HTTP/1.1 200 OK
< Date: Thu, 05 Jun 2014 03:51:31 GMT
* Server Apache/2.2.26 (Unix) mod_ssl/2.2.26 OpenSSL/0.9.8y mod_cluster/1.3.1.dev DAV/2 is not blacklisted
< Server: Apache/2.2.26 (Unix) mod_ssl/2.2.26 OpenSSL/0.9.8y mod_cluster/1.3.1.dev DAV/2
< Allow: GET,HEAD,STATUS,INFO,OPTIONS,ENABLE-APP,DUMP,REMOVEID,REMOVE-APP,DISABLE-APP,POST,ERROR,PING,STOP-APP,ADDID,CONFIG
< Content-Length: 0
< Content-Type: httpd/unix-directory
< 
* Connection #0 to host 127.0.0.1 left intact
````

by registering methods with apache, methods could be compared now more efficiently, by switching to method_number() compare instead of strcmp() on a method string.
OK I will make some tests (run the testsuite on fedora 20) and merge it if it is OK.