Allow Netware awk script which handles proxy

symbol import/export to differentiate between
hooks which call APR_HOOK_LINK() in the C
files and those who don't by marking them
in the header file.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1728656 13f79535-47bb-0310-9956-ffa450edef68