Removed 'method bits' hack from ICP query/reply. This will break

Removed 'method bits' hack from ICP query/reply.  This will break
interoperability.  Instead the ICP server treats all queries as
METHOD_GET.

The ICP client code, however, uses an array of the most recent
8192 keys sent in ICP queries.  The reqnum is an index to this
array, so we can look up the key for an ICP reply easily.

Also changed storeKeyPublic and storeKeyPrivate to NOT use snprintf, but
just pass integers 'id' and 'method' directly to md5update.