Support relative dates when adding recurrences
Support relative dates when adding recurrences

In commit f5d8b5e (Support durations in recurrence ending dates,
2016-02-25), we added support for the `+xxwxxd` syntax when specifying
recurrence end dates. However, this only worked when *editing* the
recurrence, not when converting a regular item to a recurrent one. Fix
this and support the new syntax in both cases.

Also, mention the new syntax in the prompt.

Signed-off-by: Lukas Fleischer <c9ca73f8336dcfb037ec2c2abf52d80a6847a5cd@calcurse.org>

lfos/calcurse,lfos/calcurse,lfos/calcurse