Added more global parameters to /admin/unused API endpoint (formally /admin/dud)
and also managed to remove /admin/unused from API documentation UI.
Added results slicing to /assets/all
Added /assets/orderbook API call that returns open asset orders
Added /assets/trades that returns successful asset trades
Added POST /assets/issue stub
Unified HSQLDB connectionUrl to public variable inside Controller class.
Can't deploy v1 ATs with isFinished=true flag as that prevents later
transactions sending messages (during import of v1 chain).
Some future hard-fork code will need to set all v1 ATs to "finished".
Changed DB's "TransactionRecipients" to "TransactionParticipants" to
properly support API call to find all transactions 'involving' a
specific address. Support code needed in Block and Transaction with
some transaction-specific overrides for Genesis and AT transactions.
Removed old, deprecated calls from Transaction/TransactionRepository
Moved HSQLDB database properties from connection URL to explicit
SQL statements in HSQLDBDatabaseUpdates. They didn't work in
connection URL during DB creation anyway.
Retrofitted HSQLDB Accounts table with public_key column instead of
rebuilding it later.
Fixed incorrect comments in IssueAssetTransactionTransformer regarding
v1 serialization for signing.
Re-imported v1 chain to test latest changes.
