[12431] Use proper error files for missing string errors
[12433] Add support for the Rabbit Day

This adds a new config option "RabbitDay" - don't forget to set it to our
suggested value (see config file)!

Signed-off-by: DasBlub <DasBlub@gmail.com>
[12434] Add support for server-side spells attr, attr_ex, attr_ex2 and effect0_target_b columns

This will allow support for the following achievement spells:
58630, 59046, 59450, 64899, 64985, 65074, 65195, 68184 and 72845

These are only a few of the missing achiev check spells. Other spells can be added later.
(no comments to this commit, only fun ;\ /dev/rsa)
SD2 update