Implement Microservice Architecture (ZMQ/ProtoC)

[MoKob]

To allow usage of multiple independent components, we need a reasonable plug-in architecture.
From previous experience, I want to try out an architecture similar to previous experiments on public transit routing that uses protocol buffer messages, sent over IPC calls between different plugins.

This tasks consists of multiple parts:

• integrate ZMQ
  • integrate ZMQ library
  • set up IPC functionality
• enable protocol buffer
  • add protocol buffer library
  • enable protoc building into build process
  • define protocol buffer interface for plugins
• enable geometry access
  • define a protocol buffer interface to annotate graphs with coordinates