Output compile errors when signed integer types are used on functions
where the answer might've been a complex number but that functionality hasn't
been implemented.
This applies to sqrt, log, log2, log10 and ln.
A test which used a signed integer was also changed to use an unsigned
integer instead.
Comparisons with absolute epsilons are usually useful when comparing
numbers to zero, for non-zero numbers it's advised to switch to relative
epsilons instead to obtain meaningful results (check [1] for more
details).
The new API introduces approxEqAbs and approxEqRel, where the former
aliases and deprecated the old `approxEq`, allowing the user to pick the
right tool for the job.
The documentation is meant to guide the user in the choice of the
correct alternative.
[1] https://randomascii.wordpress.com/2012/02/25/comparing-floating-point-numbers-2012-edition/
This change was mostly made with `zig fmt` and this also modified some whitespace. Note that in some files, `zig fmt` produced incorrect code, so the change was made manually.
