Bug 16843: Help for EDIFACT messages

Bug 16843: Help for EDIFACT messages

To test:

1) Go to Acqui -> EDIFACT messages
2) Click Help in top-right corner
3) Confirm that Help window opens with appropriate help text
4) Confirm link to manual works as expected

Sponsored-by: Catalyst IT
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 1c80cef03260351ef8b2f129e10c01f88986875a)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>