Fixes and improvements to SDEPLOT

More efficient. User should be able to switch windows during simulation.

Signed-off-by: Andrew D. Horchler <adh9@case.edu>
Three new output functions

Phase plane/space output functions and a command window printing function. Very similar to functionality of ODE suit, but better.

Signed-off-by: Andrew D. Horchler <adh9@case.edu>