Add an option "-encoding" to the wrapper application
which tells the wrapper (and consequently the wrapped
application) in which encoding a wrapped file is in.
Allow multiple specifications of this option, and each
specification affects all files specified afterward.
This is like the handling of "-relativeto".
The reason for this FR is bug #227408. Instead of
having the application guess the encoding or using a
fixed encoding (both of which will always be wrong in
certain cases) have the user provide this information
and then use that when reading a wrapped file.