Add clinical-commit-to-loinc.xml helper scripts

- generate_cctl.py generates the XML from a CSV
- cctl_to_csv.py writes out a CSV from an XML

Careful, the CSV from cctl_to_csv.py cannot be read in by
generate_cctl.py without modification.
Add support for 3-col CSV to generate_cctl.py
Merge pull request #56 from ufl-taeber/master

Add clinical-component-to-loinc.xml helper scripts