Ed25519 ported to Java
This class was ported from the Python Ed25519 reference implementation, located at http://ed25519.cr.yp.to/python/ed25519.py
It is not meant to be a proper OOP Java class, but rather a (mostly) direct translation from the Python code.
Compile and run test.java, and compare the output to validtest.txt - if it matches, you have a working Ed25519 library.
This code is released to the public domain and can be used for any purpose.