added support for validating patient import against patient manifest and returning list of missing patients
fixed errors that were causing bulk import tests to fail
Merge branch 'import-archive-validation'

Rebasing and merging pull request #175
Whitespace clean up
Add documentation for new QDM subset code extension
Now indexing the patient_cache by medical_record_id
Merge pull request #177 from projectcypress/qdm_subset_codes_doc

Add documentation for new QDM subset code extension
merge codes and concat values when de-duping encounters
Merge pull request #179 from pelargir/smarter-encounter-dedup

Smarter de-duping of encounter entries
Merge pull request #178 from projectcypress/patient_cache_tweaks

Patient cache tweaks