Test driver for Digital Signature Algorithm operations.

This program generates DSA keys (currently, of a few compiled-in
sizes) and does timing tests on DSA operations.

The command line is a seed string which is used to generate the
public parameters.  The use of a seed lets you verify that the
key was not generated in a weak manner.

Currently, the list of key sizes to generate is compiled in.

After key generation, the program DSA-signs and verifies a
random message, and displays the timing.

Example invocation lines:

dsatest arbitrary seed string
dsatest foo