As we're trying to make all pop and imap servers use pam files provided by mailbase-0.00-r8 (bug 79240, for example), attached is a patch for dovecot. It makes the ebuild modify the dovecot.conf file, so dovecot uses proper pam files, instead of installing and using its own. Grant, if you're okay with it, I can commit 0.99.14-r1 with this patch myself, if you don't have time.
Created attachment 51991 [details, diff] patch for dovecot-0.99.14.ebuild
I assume that you're also going to depend on the proper version of mailbase? Assuming so, then please go right ahead. Thanks!
Ah, right, I forgot to include that in the patch. My bad. :) BTW, perhaps the sed receipt should be a little more specific, to allow for future upstream configfile changes (more lines ending with "pam").
dovecot-0.99.14-r1.ebuild is in CVS.