add [flags] to syntax

per http://httpd.apache.org/docs/2.4/mod/mod_rewrite.html#comment_5728

split list of flags out of the massive CondPattern list.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1757838 13f79535-47bb-0310-9956-ffa450edef68