Increase quest-state.

Syntax1:\\
qadvance(argument[string])\\
Where argument has the format: '[victim] [id] [increment{optional}'\\
Accepts [[:lua:formatargs|format arguments]].

Syntax 2:\\
qadvance( victim<CH>, id<string/number> [, increment<number>] )

Notes:\\
Id can be a numerical vnum or relative vnum.

Examples:\\
mob:qadvance("%s 31404", ch.name)\\
mob:qadvance("%s 31404 3", ch.name)

mob:qadvance(ch, 31404)\\
mob:qadvance(ch, 31404, 3)