changed misc.diag_nd to use a for loop on the domain, which will be collapsed.

Added misc.rat to compute rational approximations of real numbers

Added quantity.EquidistantDomain to simplify the initialization of a domain with a certain step size

Fixed signals/SmoothStep to use spline wise interpolation instead of symbolic computation

numeric.interpolant: added new evaluation function interpolant.eval that bevaves the same way as the griddedInterpolant. I.e., only if the arguments are passed in a cell array, they are interpreted as grid. If they are passed as a list, they need to have the same length and are evaluated pairwise.
Patching the existing evaluate function is considered as not recommendable due to the missing downward compatibility.

Initial checkin of the matlab library for the control and faultdiagnosis of infinite dimensional systems