Abstract LTI system types should be parameterized by TimeEvol

[baggepinnen]

If they are not, one can not dispatch on, say, AbstractStateSpace{Continuous} and have to either

• Dispatch on StateSpace{Continuous} and reimplementing for other types
• Check iscontinuous inside the method

[olof3]

Sounds reasonable. Shouldn't also LtiSystem be parameterized by TimeEvol? I think that I discussed that with @mfalt and he had some reason for not doing it or was it just that we should wait for a bit?

[baggepinnen]

I think it should (LTISystem{TE}), unless a compelling reason not to appears.

[mfalt]

I can't see any reason why not right now