Rewriting the error handling in planner.c

Printf is not a way to issue warnings and errors. This is a very late
addition but seems necessary for a viable release of the planner.

This also adds one artificial limit and two warnings:

a) no dives deeper than 400m
b) warning of potentially very long calculation times for dives longer
   than 3h (180min) before the ascent and dives deeper than 150m

It also creates quite a number of new strings that need to be translated
(and marks a few existing ones for translation as well).

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Support deeper stops and longer dive notes in planner

Since we now support dives all the way down to 400m we should also support
deeper stops. And of course this can create insanely long dive plans, so
make sure there is plenty of space for those.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Make planner.c warning consistent

Just a tiny change to make them look more consistent.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Merge branch 'planner-fix'
Update PO files for planner.c changes

Sorry, ten new strings.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
German and Swiss-German translations for the new strings

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>