message: add libzerocoin sources to Makefile.am
  Note that this needs refactoring. It should be properly sectioned as a standalone library.
diff: @@ -332,6 +332,15 @@ libbitcoin_common_a_SOURCES = \
  script/standard.cpp \
  script/script_error.cpp \
  spork.cpp \
  + libzerocoin/Accumulator.cpp \
  + libzerocoin/AccumulatorProofOfKnowledge.cpp \
  + libzerocoin/Coin.cpp \
  + libzerocoin/CoinSpend.cpp \
  + libzerocoin/Commitment.cpp \
  + libzerocoin/ParamGeneration.cpp \
  + libzerocoin/Params.cpp \
  + libzerocoin/SerialNumberSignatureOfKnowledge.cpp \
  + libzerocoin/SpendMetaData.cpp \
  $(BITCOIN_CORE_H)
  # util: shared between all executables.
  