Refactoring of SLM

- Methods moved to ServiceModelUtils to avoid duplication of code/effort
- Two new properties added to platform properties
- Service Discovery/Registry now makes a better distinction between
searching for all services in your CSS and events in a specific CSS
node.
- Fixes to SLM part of the webapp
- Major clean up of OsgiRegistryListener, including using non-deprecated
methods to interact with Privacy Manager and Security Manager
- The way the SLM handles service client files is completely changed. It
now either expects a valid URL in the serviceClient metadata field, or
will look inside the server jar/war for the client files, copy them
locally and then tell the Security Manager to register them in the DA.
- More robust SLM, with better error-handling, logs and clean-up