
This is to support streaming VHD tgz files to/from XAPI. In this way, it will avoid the restriction that SRs must be file system based SR (e.g. ext and nfs) for XenServer OpenStack. So that we can support other types of SRs e.g. lvm, iscsi and etc. Change-Id: I2cfe7340d48071bf96bc7ba0ad19f5a0b12b5378