Update scripts for postfix+courier and postfix+dovecot for gentoo.

Changes here include:
- shorten some repetitive commands (gentoo.inc.php)
- maps uid/gid from database instead of statically on main.cf
- maps 'homedir' from database instead of statically in
  vmail_mailbox_base (concatenates 'homedir' and 'maildir' columns from
  mail_users table)
- update mysql query files to use strictly postfix 2.2+ new format
  (in accordance to http://www.postfix.org/mysql_table.5.html)

templates/misc/configfiles/gentoo/postfix_dovecot/etc_postfix_main.cf

@@ -58,13 +58,13 @@ virtual_transport = dovecot
 dovecot_destination_recipient_limit = 1
 
 # Virtual delivery settings
-virtual_mailbox_base = <VIRTUAL_MAILBOX_BASE>
+virtual_mailbox_base = /
 virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual_mailbox_maps.cf
 virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual_mailbox_domains.cf
 virtual_alias_maps = mysql:/etc/postfix/mysql-virtual_alias_maps.cf
 smtpd_sender_login_maps = mysql:/etc/postfix/mysql-virtual_sender_permissions.cf
-virtual_uid_maps = static:<VIRTUAL_UID_MAPS>
-virtual_gid_maps = static:<VIRTUAL_GID_MAPS>
+virtual_uid_maps = mysql:/etc/postfix/mysql-virtual_uid_maps.cf
+virtual_gid_maps = mysql:/etc/postfix/mysql-virtual_gid_maps.cf
 
 # Local delivery settings
 local_transport = local

templates/misc/configfiles/gentoo/postfix_dovecot/etc_postfix_mysql-virtual_alias_maps.cf

@@ -1,8 +1,5 @@
 user = <SQL_UNPRIVILEGED_USER>
 password = <SQL_UNPRIVILEGED_PASSWORD>
 dbname = <SQL_DB>
-table = mail_virtual
-select_field = destination
-where_field = email
-additional_conditions = and TRIM(destination) <> ''
+query = select destination from mail_virtual where email = '%s' and trim(destination) <> ''
 hosts = <SQL_HOST> 

templates/misc/configfiles/gentoo/postfix_dovecot/etc_postfix_mysql-virtual_gid_maps.cf

@@ -0,0 +1,6 @@
+user = <SQL_UNPRIVILEGED_USER>
+password = <SQL_UNPRIVILEGED_PASSWORD>
+dbname = <SQL_DB>
+expansion_limit = 1
+query = select gid from mail_users where email = '%s'
+hosts = <SQL_HOST> 

templates/misc/configfiles/gentoo/postfix_dovecot/etc_postfix_mysql-virtual_mailbox_domains.cf

@@ -1,8 +1,5 @@
 user = <SQL_UNPRIVILEGED_USER>
 password = <SQL_UNPRIVILEGED_PASSWORD>
 dbname = <SQL_DB>
-table = panel_domains
-select_field = domain
-where_field = domain
-additional_conditions = and isemaildomain = '1'
+query = select domain from panel_domains where domain = '%s' and isemaildomain = '1'
 hosts = <SQL_HOST> 

templates/misc/configfiles/gentoo/postfix_dovecot/etc_postfix_mysql-virtual_mailbox_limit_maps.cf

@@ -1,7 +1,6 @@
 user = <SQL_UNPRIVILEGED_USER>
 password = <SQL_UNPRIVILEGED_PASSWORD>
 dbname = <SQL_DB>
-table = mail_users
-select_field = (quota*1024*1024)
-where_field = email
-hosts = <SQL_HOST>
+expansion_limit = 1
+query = select (quota*1024*1024) from mail_users where email = '%s'
+hosts = <SQL_HOST>

templates/misc/configfiles/gentoo/postfix_dovecot/etc_postfix_mysql-virtual_mailbox_maps.cf

@@ -1,7 +1,6 @@
 user = <SQL_UNPRIVILEGED_USER>
 password = <SQL_UNPRIVILEGED_PASSWORD>
 dbname = <SQL_DB>
-table = mail_users
-select_field = maildir
-where_field = email
+expansion_limit = 1
+query = select concat(homedir,maildir) from mail_users where email = '%s'
 hosts = <SQL_HOST> 

templates/misc/configfiles/gentoo/postfix_dovecot/etc_postfix_mysql-virtual_uid_maps.cf

@@ -0,0 +1,6 @@
+user = <SQL_UNPRIVILEGED_USER>
+password = <SQL_UNPRIVILEGED_PASSWORD>
+dbname = <SQL_DB>
+expansion_limit = 1
+query = select uid from mail_users where email = '%s'
+hosts = <SQL_HOST>