Currently the administrator could only reset the generic group
status by db operation(include snapshots), this change intends
to add new admin actions to achieve these.
The patch list:
1. group API [1].
2. snapshot API [2].
3. cinder client [3].
4. documentation(this).
[1] 92bbacdcef
[2] 70171dc2ff
[3] 9820cb6f38b6a68351776c333e5deacd38c5afc9
Partial-Implements: blueprint reset-cg-and-cgs-status
Change-Id: I9b985349ccb61e51a91d47d94393b68d901ac738
085d44ba78