add more acb-related 'set' and 'contains' convenience functions

[argriffing]

Currently there's a function called acb_set_fmpz_fmpz that sets the real part and the imaginary part of a complex ball to the provided integers. There are also functions like acb_contains_fmpz.

Here are some similarly named but hypothetical functions that I'd like: acb_contains_fmpz_fmpz acb_set_fmpq_fmpq acb_contains_fmpq_fmpq acb_mat_set_fmpq_mat_fmpq_mat acb_mat_contains_fmpq_mat_fmpq_mat

Any opinions on this idea? Right now I think the acb_mat/test/t-mul.c test doesn't actually involve any numbers with nonzero imaginary parts. My motivation for posting this issue was that when I looked at improving the coverage of that test I started to want more convenience functions.

[argriffing]

Here's a PR with the tests https://github.com/fredrik-johansson/arb/pull/64. I've decided to just put the convenience functions in the test file. Maybe there does not need to be a combinatorial explosion of manually written convenience functions for all combinations of types.

[fredrik-johansson]

Those functions seem fine to me.

[rickyefarr]

Were these functions ever added?