Prepare management to JDK 9 modular structure, and cleanup after Java 6 removal

[mathieucarbou]

with the removal of java 6 support several management modules can be merged together and we can only output some relevant modules now:

Proposal of new layout:

1. org.terracotta.management:management-common

Contains:

• management-model
• management-registry
• sequence-generator
• cluster-topology

Package: org.terracotta.management.common

2. org.terracotta.management:management-client

Depends on management-common and contains:

• nms-agent-entity-client
• nms-entity-client

Package: org.terracotta.management.client

3. org.terracotta.management:management-server-api

Depends on management-common and is renamed from monitoring-service-api

Package: org.terracotta.management.server.api

4. org.terracotta.management:management-server

Depends on management-common and management-server-api and contains:

• nms-agent-entity-server
• nms-entity-server
• monitoring-service

Package: org.terracotta.management.server.impl

ALSO:

• remove obsoleted distribution module
• no more shaded statistics jar

Voltron Proxy

2 possibilities here:

1. consider it as modules apart (so that other projects can use voltron proxy)
2. or include voltron-proxy-client in management-client, voltron-proxy-common in management-common and voltron-proxy-server in management-server