modify cinder README.md
add vol/snapshot name length check
add vol/snapshot deletion check



Change-Id: I71e9c1f4af9231fd3a5378d988f3e7c9fa2327d4
add vol/snapshot name length check
add vol/snapshot deletion check

Change-Id: Ibc8d68eaa91a35ed368105077a967624eb17289e
Cache subnet mapping info between cascaded and cascading

Cache subnet mapping info between cascaded and cascading and support
multiple subnets exists in single network.

Change-Id: Id70cafe058685ea27b848d7c52a2a3c9db4a521e
Merge "Cache subnet mapping info between cascaded and cascading"