Reviewed-on: https://git.com.de/LibertaCasa/watbot/pulls/27

rand.Int() would panic when the max value is <= 0, which happens when
big.NewInt() was fed with a too large number. Avoid this by validating
the big.NewInt() return beforehand. Add error handling to all callers to
both gracefully return to IRC and to log an error message.
Rename the shadowed "max" variable whilst at it to avoid confusion.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

Reviewed-on: https://git.com.de/LibertaCasa/watbot/pulls/26

Allow the database file to reside in a user defined location instead of
requiring it to be in the working directory.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

Reviewed-on: https://git.com.de/LibertaCasa/watbot/pulls/25

Align with GetTarget() which is used in games to have consistent
handling of nicknames regardless of their casing.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

Reviewed-on: https://git.com.de/LibertaCasa/watbot/pulls/24

Print only a single message instead of one per winner to reduce chat
clutter.
Skip cashout to users who won less than the possible cashout value as
limited by the division value to avoid congratulating someone who only
gets 0.
Abort should a regression cause the logic to process an empty set of
finishers to prevent unexpected behavior.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

Reviewed-on: https://git.com.de/LibertaCasa/watbot/pulls/23

Some parts of the logic do not make use of the host column in the
players table, allow the field to be empty and do not query for an empty
value (which might return bogus entries) if no value is passed to the
lookup function.
This additionally avoids the need for the hardcoded initial host when
configuring the bot player.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>