Have handshake between decompiler and agent about version

[AurumTheEnd]

After adding a lot of operations to agent and backing them with Cli integration tests, a sort of backwards compatibility is lost when people have old agents lying around. Tests fail because people can pull new code, but not rebuild the agent.

This is of course due to the way we point to the agent with a system wide config.json file in ~/.config/java-runtime-decompiler, aside from portable images ofc.

There should be a new agent operation, with which the decompiler and agent agree on their version and thus their supported operations. Otherwise fail and prompt the user to rebuild their old agent pointed to by the config.

[judovana]

an important note, except vertsion, the agent should return also port, where it listens (although maybe the only way how to obtain it is port)

[judovana]

#218

[judovana]

value of String JRD_AGENT_LOADED = "org.jrd.agent.loaded"; would be nice to have here too Maybe finally print out jonson?-)