Removed hardcoded variable and flag validation, updated modifier cate… - #43

…gories

I can't actually test this compiles, but this does a few things:

• There's old hardcoded variable and flag validation that we can now handle with the rules. I wasn't so sure whether the flags code was completely unnecessary, but if it needs to exist, we'll need to extend it, since there's a lot of new flag effects and triggers now.
• I also removed the incorrect error flagging if you use variable effects in certain scopes
• Updated dynamically generated modifier names