The API-wise nice addition of base58 encoding learning about
private keys has as a downside that external projects get the
surprise of pulling in a lot more code.
Those that want to avoid this, while not using private keys, can
simply add
add_definitions(-DNPRIVKEY) # avoid private-key using code
to their CMake file.
Also write some new accessor methods on the baseclass.
The longer term idea is to make the server itself only use the uint160
raw version for bitcoin addresses.
For now move the encodings (between that uint160 and human-readable) to
the utils library.