Ref #3 on yoon/popHealth - CAT1 export from popHealth

- Given all measures by HQMF ID, and all patients in popHealth
  - Determines if each patient is in the IPP
  - Exports CAT1 files per patient, per measure, when they are a member of
    the IPP

- Issues:
  - I'm parsing all HQMF documents as part of the process, but it's probably
    not necessary to do this in order to match patients to IPPs. If I can skip
    this step it would shave 30-60 seconds off of the task execution time.
  - I'm having an issue where multiple CAT1 files are being generated per
    patient, where I only expect one, and the only differences (based on an
    initial glance) appear to be the effective dates. The content of the files
    is otherwise the same, it seems. This seems like a bug where the export task
    is doing a lot more work than it needs to.
Merge branch 'nmedw' of https://github.com/yoon/popHealth into nmedw