* Updated to new curve25519 scalar API
* Removed clamping from constructors; clamping is always done during scalar-point multiplication
* Updated test to reflect new functionality
* Updated changelog
* Add getrandom to bring convenience random init functions
* Fix doc name
* Rename new to random_from_rng
* Deprecate new() in favor of random_from_rng()
* Simplify constructors documentation
Co-authored-by: Ciprian Dorin Craciun <ciprian@volution.ro>