Remove dup of LVMISCSIDriver in LVMISERDriver

LVMISERDriver is almost copy of LVMISCSIDriver.

Change-Id: I27f03ba19908184e96d05e7f17e581d906fc119a
Update quota-set throw 500 error

The server doesn't check whether the parameter "quota_set" or
"quota_class_set" is in request
body.So the 500 error has been thrown.

We should catch the KeyError and transfer the KeyError to
400(HTTPBadRequest) instead of 500.

Change-Id: I01260c77efa50324f3d203888689cdb1e94d2c21
Closes-Bug: #1249971
Merge "Update quota-set throw 500 error"
Merge "Remove dup of LVMISCSIDriver in LVMISERDriver"