trac #12867: Implements random_element methods for Words and moves ._iter_
trac #12867: Rebase on 6.1.beta4
trac #12867: Doctests fixed and ... changed to ....:
Trac #12867: Rebase on 6.2.beta0
#12949: generalized Hsu congruence test for arithmetic subgroups
trac #12949 minor details
Trac #14996: Rewriting Jacobi elliptic function code, new numeric evaluation, Jacobi amplitude function
Move monsky_washnitzer.py.
Fix imports in schemes/elliptic_curves after monsky_washnitzer moved.
Update import path in schemes/hyperelliptic_curves folder.
Merge branch 'u/chapoton/12949' of ssh://trac.sagemath.org:22/sage into 12949
trac #12949 details
trac #12867: rebase on 6.2.beta5
trac #15310: Wilson's construction of Transversal Designs
trac #15310: Rebase on updated #15431
Merge branch 'u/rws/ticket/14996' of trac.sagemath.org:sage into u/tscrim/14996

* 'u/rws/ticket/14996' of trac.sagemath.org:sage:
  Trac #14996: Rewriting Jacobi elliptic function code, new numeric evaluation, Jacobi amplitude function
Fixed doctests and documentation. Additional doc cleanup.
trac #16287: Merged into 6.2.rc0
trac #12867: Bugfix
remove unused import + doctest

- the randint is now not used, so I removed the import
- I modify the string of the error as in english there is no space
  between the end of the sentence and the question mark
- I added some tests on infinite alphabet to test the errors