increase max block size and broadast rate
Fix crash: chain observer notifications should be asynchronous

Chain observers are free to yield if they wish, but nothing in the
push_block call stack should ever yield, so chain observer notifications
ought to be made asynchronously. This commit makes it so.
Fix wallet_backup_create
Update submodule
Rename COVER -> MARGIN in wallet history
Fix automatic wallet backups
Fix regression tests
wallet won't let you accidentally overpay to cover
Turn up the volume on the loggers. All logs are now level debug
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
Update submodule
Bump qt_wallet
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop
Print fees in market history
Update market order matching

Group fees less than 10,000 XTS
Use 66% of Short price as default call price rather than the collateral
USD ratio.  Initial margin should be based upon the short getting what
they asked for so there should be pleanty of margin.
Fix history running balance bug
Minor memo tweak
Merge branch 'develop' of github.com:BitShares/bitshares_toolkit into develop