Bug 5929: use branch admin email for advance_notice.pl emails

Bug 5929: use branch admin email for advance_notice.pl emails

This squash commit takes the two patches from Srdjan and adds a minor fix to work with
template toolkit variable renames.

Squashed commit of the following:

commit 2cab669d1fd072600942e1e6fbf3378944255a68
Author: Ian Walls <ian.walls@bywatersolutions.com>
Date:   Thu Jun 2 14:08:40 2011 -0400

    Bug 5929: Fix advanced_notices to use new template-toolkit compatible message names

    Uses 'item_due' and 'advance_notice' for advance notices names; letters do not send otherwise

commit caded04702d5eebd0f63a3b93cdddce28257f092
Author: Srdjan Jankovic <srdjan@catalyst.net.nz>
Date:   Tue Mar 29 12:38:49 2011 +1300

    wr77490 (bug 5929): removed debugging leftover

commit 1944de0de40f937b1d8748500f24a119390db3f0
Author: Srdjan Jankovic <srdjan@catalyst.net.nz>
Date:   Tue Mar 22 19:05:23 2011 +1300

    wr77490 (bug 5929): use branch email in preference for due notices

Signed-off-by: Ian Walls <ian.walls@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>