Fix #4: Display of available signatures
Given the parameter file
* x in range(0.1, 0.2)
the error message is now
Error: line 1, character 7:line 1, character 22: Function range cannot be applied to (0.1, 0.2) of type(float, float), the following versions are available: (int, int), (int, int, int)
(Previously, signatures were not parenthesized, and the list of
available signatures was printed int, int, int, int, int
.)