Time and Timezone synchronization across agents

[sneakers-the-rat]

Raspis (and most linux distros i think?) automatically synchronize time by default, but raspis start with their timezone set as GMT. In addition to generating data that can be hard to synchronize after the fact, this causes problems, eg. when the Subject class tries to filter old data to calculate graduation effectively.

TODO

• In an initial connection ping, we already include sending the prefs file, we should also include sending the timezone and then warn if a difference is detected
• Create a setup script that allows agents to be ntpd servers, and then to do local synchronization with ntp so that timestamps are <ms synchronized with each other
  • when a task is run from a terminal with multiple connected agents, this should probably be default
• Check for time synchronization on start of any agent, warn if not done.
  • also check for sync at the start of every task run?