ecdsa: opt for shiftRight, pow and square

In the given situations, these offer better readability, or in the case
of shiftRight, a substantial performance increase.
ec: fix point decoding for other curves
ecdsa: use shamirs trick
ecdsa: consistent parameter ordering

The bias towards moving e out of the
funciontoinadfojdfpsoidjfadoifjdspiofjdas jdifjasdifpasdfsadufhasdif
THIS NEEDS TO BE EXPLAINED AND STUFF
ecdsa: use (r, s) values directly
ecdsa: remove ECKey dependency in tests
ecdsa: remove implicit ecparams
sec: use a hashtable for lookup
sec: use BigInteger.fromHex directly
sec: fix formatting
bigi: upgrade to 1.1.0