=====================================================================
Version 1.2 - Third release on CRAN
=====================================================================

BUG FIXES:
- as.integer64.SNOMEDconcept now allows additional optional arguments,
  like the generic as.integer64 function

NEW FEATURES:
- loadSNOMED also optionally loads history and query tables from a
  SNOMED CT distribution
- New function addInactiveConcepts to add inactive concepts to
  codelists, using the history and query tables

=====================================================================
Version 1.1
=====================================================================

BUG FIXES:
- Showing a concept description caused an error if there were
  multiple descriptions for a concept and duplicate concepts in the
  SNOMEDconcept vector
- SNOMEDcodelist timestamps were set to the user-supplied date instead
  of the system time
- Error on exporting SNOMEDcodelists with single row maps that had NULL
  values. Instead the NULLs are now zero-length character vectors, which
  can be exported correctly with fwrite.
- Ensure that SNOMED environment is passed from htmlCodelistHierarchy
  to showCodelistHierarchy
- Corrected bug in hasAttribute when SNOMED RELATIONSHIP table contains
  duplicate source-type-destination triples (e.g. if some are inactive)

CHANGES:
- New vignette 'customHierarchy.Rmd' explaining how to create a custom
  SNOMED-like database to enable the hierarchical view
- Vignette shows how to obtain 'History of' terms for phenotyping
  algorithms

=====================================================================
Version 1.0 - Second release on CRAN
=====================================================================

NEW FEATURES:
- New getMaps function to map a codelist to another terminology
  system
- New htmlCodelistHierarchy function to create an interactive HTML
  file to explore a codelist
- SNOMED CT simple reference sets included in the SNOMED environment,
  with new function getRefset
- Function to load a mapping table from the NHS Digital data
  migration pack (loadREADMAPS), for mapping to Read V2 and CTV3

CHANGES:
- SNOMEDcodelist S3 data type has been redesigned to include metadata
  as well as accommodate different formats of codelists
- SNOMEDcodelist no longer includes descendants by default
- SNOMED environment now includes mapping tables and simple refsets
- Updated method of displaying SNOMED CT codelists

=====================================================================
Version 0.2 - Initial release on CRAN
=====================================================================

- Initial release
