Bug 4041: First step (staff interface): Extract address blocks to include files

Bug 4041: First step (staff interface): Extract address blocks to include files

This patch extracts the address blocks in memberentrygen.tt to include files.

To test: The overall functionality should remain the same with this patch.

In further steps, more country- or region-dependent includes could be added, along with functionality to select them using a system preference.

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>