This commit implements an allocation selection algorithm for finding
allocations to preempt. It currently special cases network resource asks
from others (cpu/memory/disk/iops).

fix: increase log rotator line scan limit

Pass client configuration to plugins through loader

AR Fixes: task leader handling, restoring, state updating, AR.Destroy deadlocks

Stat path to binary to handle raw exec driver interpolated binary path

QEMU driver plugin

Co-Authored-By: preetapan <preetha@hashicorp.com>

Co-Authored-By: preetapan <preetha@hashicorp.com>

Co-Authored-By: preetapan <preetha@hashicorp.com>

Co-Authored-By: preetapan <preetha@hashicorp.com>

Co-Authored-By: preetapan <preetha@hashicorp.com>

Co-Authored-By: preetapan <preetha@hashicorp.com>

Fixes a panic. Left a comment on how the behavior could be improved, but
this is what releases <0.9.0 did.

* Migrated all of the old leader task tests and got them passing
* Refactor and consolidate task killing code in AR to always kill leader
  tasks first
* Fixed lots of issues with state restoring
* Fixed deadlock in AR.Destroy if AR.Run had never been called
* Added a new in memory statedb for testing

tr: cleanup hook logs