tidy/fix some small stuff
add missing libs back to Makefile
fix block_work() calculation function.
remove include/bitcoin/Makefile.am that got added accidentally by merge.
added extra test for hash_number
Correct build breaks due to moved blockchain.hpp.
Merge pull request #69 from pmienk/develop

Correct build breaks due to moved blockchain.hpp.
move blockchain/blockchain.cpp to src/ to match blockchain.hpp header interface for consistency.
add trailing space for consistency
Add test generation to Makefile.am, remove extraneous _LIBADD arguments.
Merge pull request #70 from pmienk/develop

Add test generation to Makefile.am, remove extraneous _LIBADD arguments.