New wrappers

[Libor Polčák]

Hello all.

Giorgio finished the development of the improved wrapping code dealing with the 
bugs realted to early injection and reliable injection in Firefox when wisiting 
pages with CSP. See 
https://pagure.io/JS-Shield/JS-Shield/blob/nscl3/f/docs/new_wrapper.md.

Giorgio, I am little confused about wrapped_name and callable_name. Is the 
following true?

"Generally speaking, use wrapped_name whenever you need to access the original 
objects only inside
the wrapper and you do not need to pass the object to other code, such as 
`Promise` objects or
callbacks. Compared to `callable_name`, `wrapped_name` has less overhead and is the 
preferred way."

Am I right that it does not make sense to define both callable_name and 
wrapped_name?

If I got it right, I think that we should consider using only wrapped_name and providing the 
developer with an option to use the object in Promies and callbacks. E.g. providing a boolean 
option like "page_script_access" that defaults to false. The code would generate the 
X-ray code only if "page_script_access===true".

Does it make sense or not?

Thanks

Libor