Conflict resolution
Minor fixes in chain_database.cpp

Preserve order history for old blocks, and do not store cumulative fees
in transactions.
Merge branch 'dryrun9' of github.com:BitShares/bitshares_toolkit into dryrun9
Implement market price history and order history

Add backend support and API calls for getting price history (spread and
volume records for each block, each hour or each day) and order history
(listing of all filled orders)

FIXME: volume is currently always reported as 1.
Merge branch 'dryrun9' of github.com:BitShares/bitshares_toolkit into dryrun9