Added connection pooling on core, added ObsCore uytpe and ucd on XML model, added ObsCore optional columns

Added UsersManagement page for admin, added 'UCD Rebuild' functionality based on CDS web services, refactoring, removed ConversationScoped in favour of DeltaSpike WindowScoped, set version number to 1.1.0

Updated ucdvalidator library (Ucidy), changed configuration model in order to support custom UCD values. Set version number to 1.0.4

Bugfix Reload button on new TAP_SCHEMA schemas, UCD dialog improvements, protected TAP_SCHEMA entities from removal, minor changes

Manage all without JPA; move some application logic into the datalayer (in order to rename it as TapSchemaManagerAPI); started management of multiple versions of TAP_SCHEMA added documentation