Release 1.8.0

Bugfix release, would be 1.7.2, but etcd layout changes mandate it to be 1.8.0. :-)

- Change etcd layout: /config/pgs is now /pg/config, /pg/stats/* is now /pgstats/*.
  This is required to fix a rare PG history tracking issue caused by non-atomic
  delivery of etcd events sometimes resulting in `incomplete` objects in EC pools
  after mass OSD restarts. Upgrading can be performed freely, downgrade requires
  additional action: [1.8.0 to 1.7.1](https://git.yourcmc.ru/vitalif/vitastor/src/branch/master/docs/usage/admin.en.md#1-8-0-to-1-7-1)
- Fix a rare client hang on PG primary OSD switch
- Fix vitastor-nfs started using mount command sometimes not stopping automatically after unmount
- Fix vitastor-nfs mounts started using mount command sometimes hanging after daemonizing
- Fix merge/flatten into a pool with different object size (image migration between pools case)
- Do not print extra "PG disappeared after reload" verbose log messages for non-existing PGs
- Fix clustered Antietcd support and persistence filter
- Do not try to purge the same OSD multiple times if its multiple devices are passed to purge
- Various node.js binding fixes

csi/deploy/004-csi-nodeplugin.yaml

@@ -49,7 +49,7 @@ spec:
             capabilities:
               add: ["SYS_ADMIN"]
             allowPrivilegeEscalation: true
-          image: vitalif/vitastor-csi:v1.7.1
+          image: vitalif/vitastor-csi:v1.8.0
           args:
             - "--node=$(NODE_ID)"
             - "--endpoint=$(CSI_ENDPOINT)"