fix issue by outputing proper pubkey format

The way I was outputting the pubkeys would be incorrect if the first byte of
one of the coordinates was 0, since it would print the first non-zero byte
first. The solution was to use the standard openssl function that outputs a
public key to oct.
update BIP32 to be able to derive pubkeys

...using the new addCompressed interface in Key.js
remove redundant and slow test
remove commented-out code