[Jsbsim-matlab] Updated S-Function

[b m. <bri...@in...>]

OK, made some revisions to the S-Function.  Can now enter initialization params via the function's block parameters dialog box like any other S-function.  3 parameters are needed: "aircraft_name", [vector of 12 state variables], [vector of 6 control variables].  

Still a few more things to do....

Brian