Function: poldegree
Section: polynomials
C-Name: poldegree
Prototype: lGDn
Help: poldegree(x,{v}): degree of the polynomial or rational function x with
 respect to main variable if v is omitted, with respect to v otherwise.
 For scalar x, return 0 is x is non-zero and a negative number otherwise
Description: 
 (pol):small	        degpol($1)
 (gen):small	        degree($1)
 (gen, var):small	poldegree($1, $2)

