[UIMA-3969] add tests for delta cas, and fix the serialization. Change the API to have the BY_ID include EMBED_TYPE - so the type is embedded as a feature @type - this makes it possible with a ref to the FS to get the type. Make the serialization for arrays and lists be like a single feature @collection with an array value.  Change some names for uniformity - make all the names @xxx instead of some being _xxx.  Update the expected values.

git-svn-id: https://svn.apache.org/repos/asf/uima/uimaj/trunk@1618774 13f79535-47bb-0310-9956-ffa450edef68