Adding measure to test valuesets.
Initial code service interface.
Fix findbugs and pmd whinning.
Adding measure to test valuesets.
Initial code service interface.
Fix findbugs and pmd whinning.
Merge branch 'java_code_service_execution' of https://github.com/cqframework/clinical_quality_language into java_code_service_execution
Merge pull request #9 from cqframework/java_code_service_execution

Java code service execution
Add stubs for all known missing ELM operators
Refactored expressions into multiple files (organized according to ELM specification structure).
Further refactoring could be done, but don't want to cause too many merge conflicts, so stopping
here for now.  Tests should also be refactored similarly, when convenient.