#995 CIF merger gets option to control whether merged specification is a partial specification

• Best to review per commit.
• End-user visible changes:
  • CIF merger gets option to control whether merged specification is a partial specification. By default, a merged specification in non-partial. The idea is that you merge to make it a full specification, and you can just merge with multiple input files to do it in one go. If you somehow must merge some partial specifications to form a larger partial specification, you can do so by enabling the option to make the merged specification a partial specification.
• Other changes:
  • Added CifPartialSpecAnnotationUtils.

Closes #995 (closed)