New support function: ap_getword_conf2[_nc] which acts

just like ap_getword_conf[_nc] but allows for {} to be
used as word quotes. That is:

   {Hello World} Foo Bar
   "Hello World" Foo Bar

are equiv.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1722321 13f79535-47bb-0310-9956-ffa450edef68