Move the generating empty deps stuff into fastgen.sh. The .deps files

are only used by Makefiles which are created by fastgen.sh, so fastgen
is the natural place to create them.

The "portable dirname" regex has been changed to remove any number of
trailing slashes. Just in case. :)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85139 13f79535-47bb-0310-9956-ffa450edef68