Reorganized module import.
Dropped the import of constants.VERSION, when it wasn't really needed.
Centralized the import of os, re and locale in VirtualMailManager/__init__.py.
Also moved w_std() and w_err() from vmm to the __init__.py.
-- ---
-- with Dovecot v1.2.x the service managesieve was renamed to sieve
-- ---
ALTER TABLE users RENAME managesieve TO sieve;
DROP VIEW dovecot_password;
CREATE OR REPLACE VIEW dovecot_password AS
SELECT local_part || '@' || domain_name.domainname AS "user",
passwd AS "password", smtp, pop3, imap, sieve
FROM users
LEFT JOIN domain_name USING (gid);