Migrate as much of the setup.cfg file to the pyproject.toml file as w…

…e can.

Migrate as much of the setup.cfg file to the pyproject.toml file as w…

…e can.

Use reification input type to construct the output

Use the current `op` to determine which `etuple` function to use

The first argument passed to `etuple` determines which of the registered
functions is called. The first argument is generally an
`ExpressionTuple`, the etuplized version of the operator. However, when
using subclasses of `ExpressionTuple` to customize evaluation, we want
`etuple` to depend on the current operator and not its etuplized
version.

Add a method to specify ExpressionTuple evaluation function

Add a method for generic ExpressionTuple evaluation

Add rator and rands transform options to etuplize

Remove an unnecessary stack overflow-generating test

Allow generator evaluation results

Merge pull request #8 from brandonwillard/unify-kwdargs

Make keyword arguments unifiable and reifiable