request add db45/db46 support to mail/exim port

[snowcrash+freebsd]

> I have now fixed it so that the exim port doesn't need to set WITH_BDB_VER?=1 anymore.  Instead setting either WITH_BDB or WITH_BDB_VER > 1 will make the port use Mk/bsd.database.mk to choose the version of BDB to use, otherwise it will default to the system BDB.
>
> The updated patch is in PR 115427:
>
>  http://www.freebsd.org/cgi/query-pr.cgi?pr=115427

great!

Thanks!