- added CFA cpu usage discount
 - added max transaction net and cpu usage
 - refactored trace data structures to resolve cyclic dependencies in header files
 - refactored accounting code in chain controller for a little more clarity
 - refactored lock processing and put them in the associated block/transaction traces

From a script by @joneric.

abi for eosio.system contract, draft of unit-test, get_blockchain_parameters API function, asset switched to signed int64_t, fixes

added tests for the WASM currency contract and fixed issues it exposed, refactored contract initialization as a require_recipient where the logic of init vs apply is now in the wasm_interface