Add DAO implementation for Stud.IP's REST API
Implement HTTP basic authentication for StudipRestConnectorDaoImpl
Fix JSON parsing, add logging
Do not try to set up LDAP if no server URL is set
Fix NPE, handle HttpMessageNotReadableException for empty results
Ensure clean shutdown of HSQLDB
Merge branch 'hsqldb-clean-shutdown'
Merge branch 'optional-ldap'

Conflicts:
	connector-service/src/main/java/de/thm/arsnova/connector/config/SecurityConfig.java
Merge branch 'studip-rest-api'
Increase snapshot version