DEA NG
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Some differences from previous version.

-Introduces a more modular structure than the prior DEA incarnation.
-EM/fiber based concurrency used prevasively.
-Warden the only supported means of running apps.
-File downloading handled from within app container.


Live updates:

DEA updates: Sending a SIGINT to the DEA to snapshot its state and shutdown. On restart, the DEA will
resume from this snapshot, and reconnect to and resume containers in the warden.

Warden updates: The DEA depends on the presence of the warden and will shutdown immediately if
warden goes down. On warden updates, we assume containers cannot be easily resumed, so we rely