Bug 17762: Add the new TranslateNotices syspref

Bug 17762: Add the new TranslateNotices syspref

This whole patch set adds the ability to translate notices in different
languages.
That way, if a library has patrons from different countries, they will
not have to send the notices in only one language but they will be able to
translate them.

Test plan:
- Switch on TranslateNotices
- Translate the interface in different languages
- Edit patron's details
=> You should see a new "prefered language" entry
That language will be used to send notices to this patron
- Edit several notice templates
=> You should see different tabs, 1 tab per language translated at the
opac (which sounds to make sense)
- Now the notice generated for this patron should be the one translated
in the language picked for him
To confirm that, try to generate several notices for this patron.
If the notice is not translated, the default one should be used.

Sponsored-by: Orex Digital
Signed-off-by: Hugo Agud <hagud@orex.es>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>