This change makes NetworkParameters use and depend upon Network instead
of the reverse. This will allow Network to be moved to `base`.
Define `UnitTestParams` as being on the `TEST` network. We must choose
a `Network` property for `UnitTestParams` and I have learned through trial-and-error
that `TEST` is the correct choice.
This also moves Coin, Fiat, its parent Monetary and the related MonetaryFormat into the new base package.
See the provided package-info.java for details.
Deprecates DEFAULT and uses BIP32 internally where DEFAULT
had been used before.
This makes the code more clear. I think it makes sense to be
explicit when specifying a KeyChainGroupStructure and not have
a DEFAULT symbol (which implies the default might change.)
