Tests for Metadata plugin, workflow_run. Looks like it behaves as expected.

Conflicts:
	seqware-webservice/src/test/java/net/sourceforge/seqware/pipeline/plugins/MetadataTest.java
Work in progress, a couple of missing tests, some exploration of GenericMetadataSaver, with some tests in progress, and some clean-up
Tests for GenericMetadataSaver and some cleanup
Allow the Metadata plugin to check for valid parent accessions before starting to create a workflow run
Fix searchString for accession search