Support for -DUSE_HSREGEX, no hiding for the regex symbols.

Support for Linux... which incidentally has an R symbol type for read-only
data (this is a gnu feature maybe, it may even be an optional posix thing).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80388 13f79535-47bb-0310-9956-ffa450edef68