LUCENE-5911: Remove cacheing of norms, calculate up front in freeze()

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1633322 13f79535-47bb-0310-9956-ffa450edef68
LUCENE-6013: remove IndexableFieldType.indexed and FieldInfo.indexed (it's redundant with IndexOptions != null)

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/branches/branch_5x@1633328 13f79535-47bb-0310-9956-ffa450edef68