Initial implementation of Vault Persistence using Requery (#191)

* Initial prototyping with Requery as a persistence replacement for Exposed/Hibernate

Applied changes following PR review by RP

Updated timestamp naming (removed committedTimestamp) and StateStatus (removed AWAITING_CONSENSUS) after discussion with RP.

Removed FungibleState and LinearState schemas (and associated tests) - awaiting Requery uni-directional relationship fix.

Added Transaction propagation such that requery re-uses any existing transaction context.

Made requery default logging configurable (disabled by default)

Nullable fields are now truly nullable (in the Kotlin and DDL sense)

Fix for SimmValuation integration test.

Workarounds applied to resolve Requery issues when sharing Transactional context.

Addressed PR review comments from MH.

Further updates following re-review by RP/MH

Further updates following additional PR review comments by RP

Minor update following additional PR review comments by RP

Optimised makeUpdate state processing code.

Resolved conflicts after rebase.

Additional Unit tests and bug fix for correct spending of multiple contract state types within a single transaction.
Required interface change to states() API to take a setOf (ContractStateClassTypes)

Minor code clean-up.

Re-write NodeVaultService consumed state makeUpdate function using SQL.

* Resolve conflict after rebase from master

docs/source/example-code/src/main/kotlin/net/corda/docs/FxTransactionBuildTutorial.kt

@@ -13,6 +13,7 @@ import net.corda.core.crypto.signWithECDSA
 import net.corda.core.flows.FlowLogic
 import net.corda.core.node.PluginServiceHub
 import net.corda.core.node.ServiceHub
+import net.corda.core.node.services.unconsumedStates
 import net.corda.core.transactions.SignedTransaction
 import net.corda.core.utilities.unwrap
 import net.corda.flows.FinalityFlow
@@ -42,7 +43,7 @@ private fun gatherOurInputs(serviceHub: ServiceHub,
                             amountRequired: Amount<Issued<Currency>>,
                             notary: Party?): Pair<List<StateAndRef<Cash.State>>, Long> {
     // Collect cash type inputs
-    val cashStates = serviceHub.vaultService.currentVault.statesOfType<Cash.State>()
+    val cashStates = serviceHub.vaultService.unconsumedStates<Cash.State>()
     // extract our key identity for convenience
     val ourKey = serviceHub.myInfo.legalIdentity.owningKey
     // Filter down to our own cash states with right currency and issuer