XenAPINFS: Copy image from glance

related to blueprint xenapinfs-glance-integration

This change is using the glance xenapi plugin to copy a glance image to
a xenapinfs backed volume. It slightly differs from the reference
implementation, as this implementation is composed of three steps:
- create volume
- overwrite the created volume with the one downloaded from glance
- resize the volume
As opposed to fill the bytes from glance to the created image. This
approach works more effective with XenServer type semi ovf tgz -ed vhds.

Change-Id: I2345f6bb355aa285eee0455380c580e4724f004e
Print out auth token, and log image_href

Change-Id: I1602bfe6c5aa7a4c6f1d5d25f175eb1362afb0eb
Use glance.get_api_servers to get glance parameters

Change-Id: I4e32b03f1ce43b3058e59c6a2ba093252438bb6b
Log out sr and vdi uuids

Change-Id: I6420f9a609e58ad221a94ad9860a46202aba48ec
Add debug messages

Change-Id: I16f4d30661ce417e8560f6868b351451a431af58
Update local volume reference

Change-Id: I1104b52b28359ac9a896344b0125bdd4f91432f9
uuid stack creation

Change-Id: I0a063be2c64debc85e0e5900958539e648a19557
Added uuid import

Change-Id: Ibfe0844792745da78668aa63bebbcef86c406304
Log out clone_image calls

Change-Id: Iebaa80c408efe3f226f13c1fd9bf4934ba91a0fd
uuid_stack will only contain the desired vhd

Change-Id: I2648c57d968e157b81c4ecb30d0ce75d9ed36319
Ask xenapi plugin to copy image

Change-Id: I7fd556ff0149dab786ea289bf66cbbc0f8b4de0c
Typo fix

Change-Id: I98a092a84c71576509af35db377b94aef54f1654
use finally, and do not use request to call the plugin

Change-Id: Ief29f75c75d0730d72f13d1dad3dd84ffca40ea2
Fix hack

Change-Id: I9b91da0d249989cbb80f25cdbc8d29c1a7acfcef
Fix _session to -> session

Change-Id: I18068b22535b0091d20688a86b7f3b468142e80c
call_plugin

Change-Id: I1e6408bbe7ef03866b40d564916732516b84b3cb
Plugin call

Change-Id: Ibf4b0c672b653d18e31f36fdeda36a83b8f1b8ad
Print out the result

Change-Id: Ifd75607ffaeda38f4cd8f08dabbe75a50c3bc0bc
more logging

Change-Id: Iac8687027e4ca0f0b18d16faeacacc363161a8d8
more logging

Change-Id: Ia14f93e293b1efed069ed8c0e0370c1be46a3918