most initial work on v4 pubkeys completed
further v4 address work
more v4 address work. Should be done.
ignore eighteenByteRipe value if user specified numberofnullbytesonaddress in keys.dat file
small fixes to address generator and listAddresses2
raise default demanded difficulty from 1 to 2
Increment version number to v0.4.0
Merge pull request #506 from Bitmessage/encrypted_pubkeys

Encrypted pubkeys
Merge branch 'master' of https://github.com/Bitmessage/PyBitmessage
Change the accepted address versions

Update _verifyAddress to accept version 4.