fix: possible segfault in GCD when passing to extensions
fix: possible segfault when passing to extensions in sparse gcd
Merge pull request #613 from mmklee/gcd

Gcd
Added git HEAD ID to the doxygen output
chg: added pruning of alg extensions
chg: added leftShift of CanonicalForms
chg: use leftShift in computation of cyclotomic polys
chg: modular resultant for small finite fields