This command will bump up the specified guild skill by the specified number of
levels. This refers to the invoking character and will only work if the invoking
character is a member of a guild AND it's guildmaster, otherwise no failure
message will be given and no error will occur, but nothing will happen - same
about the guild skill trying to exceed the possible maximum. The full list of
guild skills is available in 'db/skill_db.txt', these are all the GD_ skills at
the end.

The flag parameter is currently not functional and it's a mystery of what it
would actually do. (Though probably, like for character skills, it would allow
temporary bumping.) Using this command will bump the guild skill up permanently.

// This would give your character's guild one level of Approval (GD_APPROVAL ID
// 10000). Notice that if you try to add two levels of Approval, or add
// Approval when the guild already has it, it will only have one level of
// Approval afterwards.
guildskill 10000,1,0;

You might want to make a quest for getting a certain guild skill, make it hard
enough that all the guild needs to help or something. Doing this for the Glory
of the Guild skill, which allows your guild to use an emblem, is a good idea for
a fun quest. (Wasting a level point on that is really annoying :D)