Function1s::Polynomial: Simplification

The coefficients in the polynomial are now specified in order of
increasing exponent, starting from the constant coefficient (i.e., zero
exponent). Exponents are no longer specified. This better fits the
definition of a polynomial, and it prevents the strange scenario when if
exponents are given as a vector or tensor or similar then the units of
the coefficients are not the same across the different components.

For example, polynomial y = -1 + x^2 + 2x^3 can be specified as:

    <name>  polynomial (-1 0 1 2);

Or, alternatively:

    <name>
    {
        type    polynomial;
        coeffs  (-1 0 1 2);
    }

applications/test/Function1/polynomial

@@ -0,0 +1,5 @@
+function polynomial (0 4 -4 1);
+
+x0 -0.5;
+x1 2.5;
+nX 51;