SESSION fixes/changes

This is for Beta's scripts in particular, though maybe I might consider using it myself now.

It fixes data being reset between reloads as well as identifyScriptAs behavior (clearing all players & channels when the scriptid is changed but not refilling). I'm pretty sure you know what I'm talking about :x

It's quite aggressive and not very efficient, probably needs some changes here and there.

Also adds a bunch of methods for scripts (clearAll, disableAll, refill, hasUser, hasChannel, dump)