Renamed three more functions to common ap_ prefix which we missed at the

Big Symbol Renaming because they're #defines and not real C functions:

     is_default_port()       ap_is_default_port()
     default_port()    ==>   ap_default_port()
     http_method()           ap_http_method().

Submitted by: Ralf S. Engelschall (Hint by Dean Gaudet)
Reviewed by: Brian Behlendorf


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@81370 13f79535-47bb-0310-9956-ffa450edef68