Assign with ellipsis arguments leads to hard to find bugs

[adeguet1]

Using:

vctDoubleMat m(3,3);
m.Assign(1, 0, 0,
         0, 1, 0,
         0, 0, 1);

leads to garbage because the last arguments are stacked as ints and the va_arg macros expect doubles. Users have to specify 1.0 instead of 1. The simplest fix is to define for Assign methods to cover signatures with more parameters, maybe up to 16? A macro can be introduced for this. Based on feedback from @zchen24 and @marcinbalicki.

[adeguet1]

One option discussed in meeting:

m.Assign(const type & element0, const type & element1 = NAN, ....) // with 16 elements

The method would check that the number of parameters that are not NAN corresponds to the number of elements in the container and then assign them. We would remove all other Assign with finite number of elements and the one with ellipsis.