Small security enhancement idea

I imagine that there wouldn't be any reason to NOT do this since I can't think of how it would break anything, so here's a small tweak that I think should be added to the core product.

For hook files, check to make sure that the hook filename doesn't have any /'s or 's in it. Basically, eliminate the possibility of a file being outside of the hooks folder. With the recent exploit discovered, in another topic, someone mentioned finding files called on as hooks. I looked and saw it had happened to me too. There were two files being called on, with the filenames pointing to a different folder location to call the malicious file. For example, ../public/photo-128.jpg was the name of one of the files. If files with the slashes were to be ignored, such attempts would be pointless. It wouldn't stop a malicious file from being run in the hooks folder, but at least it would prevent attempts to mask where it's being stored at.