Merge rust-num#95

95: Create ComplexFloat trait to model Floats as a subset of Complex<T> r=cuviper a=obsgolem

Resolves rust-num#2. Replaces rust-num#53. Nearly all the work here was already done by YakoYakoYokuYoku. I have merely updated it to master and  made a few discretionary changes which I think improve the work slightly. More unit tests will be coming.

Co-authored-by: YakoYakoYokuYoku <gc1000ll@gmail.com>
Co-authored-by: Josiah Bills <josiah@adoniram.net>
Co-authored-by: Josh Stone <cuviper@gmail.com>

Author: 4 people