RimStone 4.1.0 released

This release makes usability improvements, specifically better semantics and shorter code for calling handlers locally within an application with respect to input and output parameters.

call-handler now has "set-param" and "get-param" clauses to set input parameters and obtain output parameters in a local call.
begin-handler (or %% for short) now has "get-param" clause to obtain input parameters in the request declaration.
"return-value" clause in call-handler is renamed to "return-code" to better reflect its purpose; note that for backward compatibility "return-value" will still work until the next major release.
A new documentation item (input-output-parameters) has been added to provide more information and an example on passing information into and out of local handler calls.