Fix market engine, update how interest is paid.

Every time a withdraw is taken from a balance the full interest is paid.
added transaction scanning for interest
[GS] Fix regression tests
Fix leak of json_connection objects

For the first time, json_connections will be destroyed when we're done
with them. As an added benefit, the server now closes TCP RPC
connections it's done with.
Revise some prerequisites in the API
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
require 1 day to earn interest to limit attempts at compounding
Make CLI handle strings better, now that JSON parser rejects barewords
Somehow this didn't get included in
50e69f00e962c4ceeb993e6eb7f33a9abd96a917
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
Update submodules
Fix prompting for arguments on CLI
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
Update fc
Remove blockchain_get_balance_by_owner
check vote proportion
vote allocation and open order balance RPC api
honestly I forgot what I did
vote utilization, open orders by account, accrued interest
allow specifying ALL for account orders