fixed #387 : Rename asset tab

Renaming the asset name on click of asset tab
Hmm, I will check into it.  There is probably a limited set of warnings that we need. I use js2-mode in emacs, but I know emacs isn't for everyone!

The missing semicolon here is the the statement that starts with `var rename_file = ` and ends with the `}` on the line I commented.  For whatever reason, variable declarations need to be terminated with a semicolon, but function declarations (starting with `function function_name(...) {`) don't.