Fix Opencast/Karaf Directory Configuration

`KARAF_DATA` is used for most of the data modified by Opencast. But this is not entirely true. There are several points where either the mixing of local and shared data is problematic for distributed set-ups or where Opencast writes to files outside of `KARAF_DATA`:

Shared vs local:

• OSGi framework bundle cache (`data/cache`) should never be shared

• Solr indexes should be local

• ElasticSearch does not need to be shared

Data written outside of `KARAF_DATA`:

• KARAF_HOME/etc/jetty: Not respecting KARAF_ETC

• KARAF_HOME/instances: Directory containing child instances. Written on start-up

• KARAF_HOME/lock: Lockfile written on start-up