Allow NetApp iSCSI driver to sub-clone large volumes

The NetApp zapi used during certain extend operations has several limits
imposed on it.  Each block-range provided can only be 2^24 in size, and
there can only be 32 block-ranges per zapi call.  This fix allows the
NetApp iSCSI driver to send multiple zapi calls if necessary, to allow
for extend operations on volumes of an arbitrary size.

Closes-Bug: #1288962
Change-Id: I981d22f32cb2182112fbea3ea9880d1e8c8c91ab
init_host should be called before RPC consumer is created

Currently, the init_host method is called after RPC consumer is
created. This behavior will lead to a bug that when a rpc request
is received the manager can not handle it because the driver has not
been initialized!

Change-Id: Ieedba1adeb3dd98eb4ff78427fe347423c016469
Closes-Bug: #1271568
Merge "init_host should be called before RPC consumer is created"
Merge "Allow NetApp iSCSI driver to sub-clone large volumes"