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

push elected producers to active producers, calculate parameters elected by producers, back to canceling unstake requests instead of decreasing

Readme update - issue #1448

fix for the problem #1446

Revert "Add a find_package(Clang) for abi_generator"

Add a find_package(Clang) for abi_generator

Test framework improvement - stat576

Test porting

Re-updated submodules that were lost merging #1421

Update contracts.dox

Fixed typo in line 33.  "give" to "given"

P2p queue unity master

Make Jenkins only run one build's tests at a time.