* Partial (ie. incomplete) implementation of Aggregate Functions.
* Completed implementation of Aggregate Functions (sum, count, max, min, avg) with optional grouping.
* Completed Java DSL and associated JUnit tests.
* Added optional sorting by aggregate function.
* Added Jvm filename annotation on QueryCriteriaUtils.
* Added documentation (API and RST with code samples).
* Incorporating feedback from MH - improved readability in structuring Java and/or queries.
* Remove redundant import.
* Removed redundant commas.
* Streamlined expression parsing (in doing so, remove the ugly try-catch raised by RP in PR review comments.)
* Added JvmStatic and JvmOverloads to Java DSL; removed duplicate Kotlin DSL functions using default params; changed varargs to lists due to ambiguity
* Fix missing imports after rebase from master.
* Fix errors following rebase from master.
* Updates on expression handling following feedback from RP.
* Fix https://github.com/corda/corda/issues/949 by providing a default StateStatus argument to all QueryCriteria types.
* Abstracted Common Criteria into its own abstract data class + associated visitor.
* Incorporating feedback from RP PR review.
