Systemd units, limits, and bin path fixes

* Add restart for weave service unit
* Reuse docker_bin_dir everythere
* Limit systemd managed docker containers by CPU/RAM. Do not configure native
  systemd limits due to the lack of consensus in the kernel community
  requires out-of-tree kernel patches.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

roles/etcd/templates/deb-etcd-docker.initd.j2

@@ -15,7 +15,7 @@ set -a
 PATH=/sbin:/usr/sbin:/bin/:/usr/bin
 DESC="etcd k/v store"
 NAME=etcd
-DAEMON={{ docker_bin_dir | default("/usr/bin") }}/docker
+DAEMON={{ docker_bin_dir }}/docker
 DAEMON_EXEC=`basename $DAEMON`
 DAEMON_ARGS="run --restart=on-failure:5 --env-file=/etc/etcd.env \
 --net=host \
@@ -50,7 +50,7 @@ do_status()
 #
 do_start()
 {
-    {{ docker_bin_dir | default("/usr/bin") }}/docker rm -f {{ etcd_member_name | default("etcd-proxy") }} &>/dev/null || true
+    {{ docker_bin_dir }}/docker rm -f {{ etcd_member_name | default("etcd") }} &>/dev/null || true
     sleep 1
     start-stop-daemon --background --start --quiet --make-pidfile --pidfile $PID --user $DAEMON_USER --exec $DAEMON -- \
         $DAEMON_ARGS \