Upgrade to pynac-0.6.4

[rws]

Newest pynac does:

• fix Re/Im(tanh) (#20098) (R. Stephan)
• fix positive+integer assumption conflicts (#20132) (A. Thakkar)
• from GiNaC: [bugfix] fix elusive bug in quo, rem,... (R. Kreckel)
• from GiNaC: [bugfix] fix sqrfree(poly) for zero polynomials in disguise. (R. Kreckel)
• sin/cos/tan of numeric: reduce mod 2*pi (#20099) (B. Hackl)
• more trigonometric simplifications (#20099) (B. Hackl, R. Stephan)
• always expand function arguments (B. Hackl)
• exp of numeric: reduce mod 2*pi*I (#20099) (B. Hackl)
• performance: speed up sin/cos/tan/coth/acoth evaluation (R. Stephan, A. Thakkar)
• performance: GiNaC functions for coth/sech/csch/acoth/asech/acsch (R. Stephan, A. Thakkar)
• AUTHORS updated

​https://github.com/pynac/pynac/releases/download/pynac-0.6.4/pynac-0.6.4.tar.bz2

[rws]

New commits:

​9db23de	package version / checksum
​7785109	coth/acoth BuiltinFunction --> GinacFunction and fixes
​2fab819	doctest fixes

[behackl]

The interface changes on this ticket are relatively straightforward, and I could easily review this. However, I'm not sure whether I should, as I've contributed to the pynac release. What do you think?

[rws]

In principle I have already had a look at your changes, but I would like to see a third opinion as well.

[rws]

New commits:

​fcb8d95	a42f798 still fails three in expression.pyx
​bf73f41	adapt doctest to have a different arcsech() expression
​65023a5	Merge branch 'develop' into for-pynac-0.6.3
​1de52c3	expand doctest change
​075374f	add doctest
​6af66d6	add doctests for issue 144
​1f61a24	sech/csch changes
​f061a28	pynac-0.6.4 pkg version/chksum

[jdemeyer]

The whole point of this doctest is lost:

        Here arccoth doesn't have 1 in its domain, so we just hold the expression:

            sage: elliptic_e(arccoth(1), x^2*e)
            elliptic_e(arccoth(1), x^2*e)

I would remove the sentence "Here arccoth doesn't have 1 in its domain, so we just hold the expression:"

[jdemeyer]

Unless I'm missing something, this doctest looks gone:

            sage: diff(asech(x), x)
            -1/((x + 1)*x*sqrt(-(x - 1)/(x + 1)))

[jdemeyer]

Don't forget 7

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​0791a61

Merge branch 'develop' into t/20134/20134-1

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​9cbedc7

20134: fix/add doctests