Fix a test
Avoid overwriting loop limit and increment.
Eliminate few uses of $Lisp
Fix signature of 'degree' in DeRhamComplex.
Add R. Rioboo's cylindrical algebraic decomposition.
Activate PolynomialFactorizationExplicit for Integer
Change interface to CLINDEP
Fix integration of unevaluagted derivatives.
Fix handling of dummy variables in CLINDEP
Fix gcd failure due to bad reduction.