use files.prefix everywhere

glsl/files.js

@@ -79,7 +79,7 @@ files.create = function(name, content) {
  files.current = name;
  
  var file = { "name": name, "content": content, readonly: false };
  localStorage["/papill0n.org/shaders/" + name] = content;
  localStorage[files.prefix + name] = content;
  return file;
}