fix permisions, reviewer patches
export variables
#16280: Fix call for FiniteEnumeratedSet's of plain Python objects
trac #16277: Reviewer's remarks
fix search path, add tests
#16280: Trivial doctest fixes
Merge branch 'develop' into ticket/13528
Trac 15061: Use Sylvester matrix for resultant when pari fails
Trac 15061: move lcm and resultant methods to more specific classes
Trac 15061: use Sylvester matrix for resultants of multivariate
polynomials over base rings without conversion to Singular
fix magma(P) for P a multivariate polynomial ring
fix various Magma doctest failures
Trac 15061: delete an irrelevant doctest
16281: rewrite projective planes (as 2-designs)
trac #16269: Merged with #16280
remove deprecated code from #11033
remove deprecated code from #8930
remove deprecated code from #13211
remove deprecated code from #12587
remove deprecated code from #7371 and #10334