Main changes:
- added zero state message to several lists
- fixed regression with queries to search using null_flavour
- fixed SNOMED service
- added missing permissions
- added visualization of commit logs
- added data indexing for PARTY_IDENTIFIER.identifiers
- added OPT indexing of DV_INTERVAL nodes
CHANGELOG: https://github.com/ppazos/cabolabs-ehrserver/milestone/24?closed=1