This patch introduces tripleo_common.utils.{glance,nodes} modules.
The glance one is imported with only import fixes (including importing
a private exceptions module from the glance client).
The nodes.py is a rewritten and fixed version taken from
https://review.openstack.org/#/c/263309/. Main changes:
* Stop hardcoding flavor (e.g. agent, pxe) for each driver
* Support only generic properties with pm_* names. Driver-specific things
should stay with their prefix. Existing pm_* driver-specific things
were deprecated.
* Pass through everything that starts with driver-specific prefix to
node's driver_info.
* Dropped handling Conflict exceptions - ironicclient is doing it for
some time already (and does better job in it).
* Issue a specific exception for malformed instackenv.json.
* Optimize calls to ironic (use list with details instead of list+get)
* Use 'add' operation instead of 'replace', as it allows both adding
and overwriting (despite its name).
* Fixed some small issues like adding a dict to a set.
Change-Id: I7efffc5c6627776a20fad4bf4cf266330c4b8b6b
