Milestone 1 ; Bitcoin script engine; Spark integration

Supports Bitcoin reading/writing block files.

• Block file parser, serializer.
• Transaction script parser, serializer, executor.
• Tested with blkNNNNN.dat files written by Bitcoin reference implementation.

Supports following transactions.

• P2PK, P2PKH, P2SH.
• Multisig.

Spark integration.

• Run transaction analysis on Spark