a31b70c4b8
* Add an optimized squaring routine under the `sqr` name. Algorithms for squaring bigger numbers efficiently will come in a PR later. * Fix a bug where a multiplication was done twice if the threshold for the use of Karatsuba algorithm was crossed. Add a test to make sure this won't happen again. * Streamline `pow` method, take a `Const` parameter. * Minor tweaks to `pow`, avoid bit-reversing the exponent.