Beginning with this new major version, samba is configured to use
an external tdb, thus depends on opt/tdb now.
Unfortunately this breaks the build of samba, because you have to
do a forced-install of tdb first and update samba afterwards, or
remove samba first, next install tdb and samba.
The default passdb backend has been changed to 'tdbsam'!
That breaks existing setups using the 'smbpasswd' backend without
explicit declaration. Please use 'passdb backend = smbpasswd' if
you would like to stick to the 'smbpasswd' backend or convert your
smbpasswd entries using e.g. 'pdbedit -i smbpasswd -e tdbsam'.
Release notes: http://www.samba.org/samba/history/samba-3.4.0.html