Differences of unsigend numbers

[Th1nkP1nk]

There are some calculations with unsigned integers that may lead to unintended behavior.
E.g., try with a group name with less than 5 characters.

draw_headline("group",get_group_by_gid(get_current_gid()).unwrap().name().to_str().unwrap().len() - 5, true);

[Will]

This should be an easy fix by getting the largest group name size inside the directory and subtracting the length of the current file from it.