Add suport for cas.
fix bug of replace-str
Fix bug for read ceph.conf and getip script.
Fix Bug: JIRA VSM-20
Add erasure code status to storage pools in DB
Update erasure code status by timer
Update erasure code status when create erasure code pool
Add quota and cache tier to storage pools in DB
Fix bug:JIRA VSM-28
Fix bug:JIRA VSM-34
Fix bug:JIRA  VSM-35
Fix bug: JIRA VSM-36 Enable reset server status button  when server status is error
Add cache tier UI
Fix Create User Page
add vsm high level design doc