Separated different types of dates into more maps in preparation for
improving data download.
Merge branch 'master' of github.com:ONSdigital/tredegar
Merge branch 'master' of github.com:ONSdigital/tredegar
Print out exception stack trace.
Merge branch 'master' of github.com:ONSdigital/tredegar
Merge branch 'master' of github.com:ONSdigital/tredegar
Implemented "custom range" downloads in CSV and and XLSX format.