Bump to 1.3.16... Could not do a *complete* retagging of the

1.3.15 tree ("APACHE_1_3_15 already exists on version 1.898 :
NOT MOVING tag to version 1.899", for example) so we need
to bump to 1.3.16 and release that.

PR:


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@87770 13f79535-47bb-0310-9956-ffa450edef68