Remove WWW entries moved into port Makefiles
Commit b7f05445c00f has added WWW entries to port Makefiles based on
WWW: lines in pkg-descr files.
This commit removes the WWW: lines of moved-over URLs from these
pkg-descr files.
Approved by: portmgr (tcberner)
Update search.cpan.org WWW: entries to have a trailing slash.
Change some URLs from author dirs to dist dirs.
The example in the porter's handbook didn't have the trailing slash;
mea culpa for not having caught that when it went in.