Singular.jl 0.4.5 released

Today Singular.jl 0.4.5 has been released.

Diff since v0.4.4

Summary of changes

• Singular.jl should no longer crash on the new rings that Singular and its libraries can create, or at least it should crash in far fewer cases. At a lower level, this means that we have the internal function create_ring_from_singular_ring for turning a libSingular.ring_ptr into a bona fide Ring.
• Singular’s algebraic extensions of QQ and Fp can now be constructed via the function AlgebraicFieldExtension. This function takes a univariate FunctionField and a minimal polynomial in the function field to create the algebraic extension.
• Various small bugs have been fixed.

Closed issues:

• isnegative in src/number/n_Zp.jl calls isless, which is not defined (#50)
• Radical of an ideal (#101)
• Provide an up to date version of the documentation (#125)
• double definition (#308)

Merged pull requests:

• creating rings from the rings that singular creates (#336) (@tthsqe12)
• CI: test against Julia 1.6, too (#346) (@fingolfin)
• First try on calling Singular libraries with arrays as arguments (#358) (@raulepure)
• Remove ad hoc arithmetic functions (#365) (@fingolfin)
• Remove nonsense isnegative methods (#366) (@fingolfin)
• fix banner - it was 82 chars wide (#367) (@tthsqe12)
• start algebraic extensions (#369) (@tthsqe12)
• Bump AA/Nemo version and prepare for 0.4.5 (#374) (@thofma)