Minor DBMS fixes

Use bigint and bigserial (64bit)
Rename "primary" to "is_primary"
Merge branch 'develop' of github.com:joelkuiper/addis into develop

* 'develop' of github.com:joelkuiper/addis:
  Minor DBMS fixes
Use concept mapper ideas for concept types

- Indications, drugs, units are now concepts. Tables are updated accordingly. Concepts will be moved to a different concept_mapper WS, but for now they reside in this database. 

Ultimately these should be concept urls instead of a local table.
Update dbms documentation
Fix automatic regeneration of dbms postgres docs
Use uuid's for concepts 

- Minor cleanup
Use concepts in XSLT 

- Appears to work for both hypertension and depression sample
Update documentation
Minor cleanup in DBMS structure

More consistent referencing
Merge branch 'develop' of https://github.com/joelkuiper/addis into develop
Add serialization of SMAA model to JSON 

- Can be used in the new MCDA web elicitation
Merge branch 'develop' of https://github.com/joelkuiper/addis into develop
Spell correction
Update README and HEADER
Version to 1.16.4-SNAPSHOT