ENT-2320 state contract identification (#4285)

* Enforce state/contract agreement validation

* Fix some broken tests

* Ascertain targetVersion by inspecting the jar source of the ContractState

* Docs added and rebased against master

* contextLogger doesn't work here

* Java examples in docs

* Label IRSState with owning contract

* Fix rst formatting

* Add @BelongsToContract annotation to PortfolioState

testing/test-utils/src/main/kotlin/net/corda/testing/internal/vault/VaultFiller.kt

@@ -310,6 +310,7 @@ class VaultFiller @JvmOverloads constructor(
 
 
 /** A state representing a commodity claim against some party */
+@BelongsToContract(Obligation::class)
 data class CommodityState(
         override val amount: Amount<Issued<Commodity>>,