The error messages are really bad, but it's extremely difficult to
produce good error messages without the original HCL.

Also add missing SetDriverNetwork calls.

Implement client agent restarting

Defensively update alloc status whenever killing all tasks.

For lifecycle operations such as Restart and Kill, the client should not
expect driver plugins to be well behaved and close their waitCh on
context cancelation. Always wait on the passed in context as well as the
waitCh.

ShutdownDelay must be honored whenever the task is killed or restarted.
Services were not being deregistered prior to restarting.

Task restoring works but dead tasks may be restarted

update preemption tests to use new node resource structs

also includes a fix to remove unnecessary subtraction of network mbits

Preemption for system jobs

Fixing mistake in reschedule doc

Register exec driver plugin among some fixes

Also added test case

Fix driver naming, fingerprint output, races/tests

UI: build time performance improvements

also removed now unused method

UI: Reset page query param on search

Update changelog with GH-4819