S256Point Class Doesn't Store Whether or Not It's Compressed/Testnet

[mflaxman]

This is simplest and makes sense for 99% of use-cases, but it does have a strange side-effect:

>>> from buidl.ecc import PrivateKey
>>> PrivateKey(secret=1, compressed=False).point.address()
'1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH'
>>> PrivateKey(secret=1, compressed=False).point.address(compressed=False)
'1EHNa6Q4Jz2uvNExL497mE43ikXhwF6kZm'

also

>>> PrivateKey(secret=1, testnet=True).point.address()
'1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH'
>>> PrivateKey(secret=1, testnet=True).point.address(testnet=True)
'mrCDrCybB6J1vRfbwM5hemdJz73FwDBC8r'

Likely a no-fix since uncompressed keys have been deprecated for many years (and testnet is also default opted out out and not the main use-case), but wanted to at least document the unexpected behavior.