Fix captures to prevent shutdown cores

cleos system voteproducer approve/unapprove #3123

nodeos test improvements. Test for decoding packed transaction.

Tighten check for transaction finalization, iterate through blocks to narrow down transaction to a finalized block. Add test of cleos get block to verify it decodes the packed_transaction.

Multisig optimization (#3136) and system contract upgrade test (#1962)

Remove can_freeze,recall,whitelist from eosio.token

Build fedora: extended error validation

Broadcast transactions immediately upon chain acceptance

Create constitution.md

The net code previously expected that accept_transaction() would fire a signal indicated the chain accepted a transaction. This signal would then cause bcast_transaction to 1) mark in local_txns that this node has seen said transaction and 2) broadcast the transactions to the other peers

The problem is that post-slim accept_transaction() no longer fires a signal for acceptance but instead an app channel message that is wired up to transaction_ack() in the net code. There is a subtle breakage here that app channels are dispatched via the event queue — not immediately like signals. This would sometimes cause transactions to enter the event queue more than once before transaction_ack() was called. This would then cause chain::controller to fire exceptions of duplicate transactions that bleed all over the log output.

By calling bcast_transaction() immediately after accept_transaction(), local_txns will be populated with the accepted transaction before returned to event loop.

merging master into eosio_build_fedora

Issue3014

Updated comment, corrected precision

Add test for 'get account'.

eosio.msig contract: proposals table separated into two tables (now it's possible to upgrade system contract using 8Mb of shared memory) #3136

Merging master into eosio_build_fedora