FXBox initial release

My Niagara-Like particle editor is out now.

Scary

Launching something like this that could potentially get a lot of use in other peoples projects is scary but I still did it. I hope it is received well and people make some cool stuff with it, I've been testing it for awhile in Hobnobbers so it should be pretty stable but there's a few issues. Namely:

- Size of the editor window on startup is weird
- Sometimes you can't click back into the editor on the first try.

I will do my best to fix all issues and improve and maintain the tool in the coming months and maybe years.