Use timer rather than polling for delegate block production loop
Also run delegate loop only when at least one delegate has block
production enabled
Merge branch 'master' into delegate_loop

Conflicts:
	libraries/blockchain/include/bts/blockchain/config.hpp
	libraries/client/client.cpp
	libraries/wallet/wallet.cpp
Fix wallet::enable_delegate_block_production
Fix delegate block production loop
Merge branch 'master' of github.com:BitShares/bitshares_toolkit

Conflicts:
	libraries/blockchain/include/bts/blockchain/config.hpp
Merge pull request #397 from vikramrajkumar/master

Re-architect delegate block production loop