VMware: Usng RetrvProprtisEx & does multi ESX scan

The existing code uses deprecated API RetrieveProperties for querying through
property collector. The public doc asks to use RetrievePropertiesEx instead.

RetrievePropertiesEx works by retrieving results in serveral batches rather than
retrieval in a single API call. This works well in environments containing
large number of VMs or ESX hosts.

There are three steps involved 1. Get first batch 2. Continue retrieving using
a token 3. Cancel retrieval when not needed

Batch size is user configurable, default is 100 results per batch.

The review also fixes a careless programming error leading to scanning only
1 ESX host under the vCenter server for datastores.

Fixes bug: 1227078
Fixes bug: 1229654
DocImpact

Change-Id: I85a6f6a7e2d764b9843efbd0dd347fba3ef19310
Create volume revert fails for non admin user

Done fixes in revert method of EntryCreateTask task
to use elevated context while destroying volume.

Fixes bug #1230159

Change-Id: I41b7f2ae4e0235df40bcdaa511256775228751aa
Clean CONF out of brick initiator

This is part 1 of the work needed to
remove CONF from the brick subproject.
This patch removes the CONF usage
completely from the initiator portion of brick.

Change-Id: I62cf72214db9d4296ae4c5b09bd21fb53664c117
Partial-Bug: #1230066
Pass through args and kwargs in brick connectors

This is a change needed to help remove CONF usage
in the brick/remotefs/RemoteFsClient.
RemoteFsClient can then pull the values from the caller.

Change-Id: Ie1ff2a39b92c4150fec4a3191367797a260b30ec
Partial-Bug: #1230066
Remove CONF from brick remotefs

Move the remotefs CONF options back into their
corresponding volume drivers.

Partial-Bug: #1230066
Change-Id: Ie37a803dc0f895ffd9dc2c7daf8255e6096ccee2
Merge "Clean CONF out of brick initiator"
Merge "Create volume revert fails for non admin user"
Merge "VMware: Usng RetrvProprtisEx & does multi ESX scan"
Merge "Pass through args and kwargs in brick connectors"
Merge "Remove CONF from brick remotefs"