* move isinf and isnan to new branch
* sneak a roll documentation fix in
* add to docs
* update test coverage for detect_positive and detect_negative
* add types to isinf args
* move hardsigmoid to new branch
* add to test
* add NOTE to mention differing values for alpha and beta that match torch
* shift from relu6
* correct shift implementation
* or we just use relu? no more 666