Merge branch '3.1.3-trash@@2' into '3.1.3'

add storagetrash interface

See merge request zstackio/zstack!3926

Merge branch '3.1.3-trash@@2' into '3.1.3'

add storagetrash interface

See merge request zstackio/zstack!3926

Add account resource ref for vxlan

For UI developing.

Enhance update cpu memory allocate log

add FlatDhcpUpgradeExtension

fix hostname for flat network provider when creating vm

upgrade agent version to 1.0

don't delete ceph pool by default when deleting the ceph primary storage

fix unit test