Made changes to instance add/edit code to remove AR Objects from @edit

- Changed code to add/edit Instance to not store AR Objects in @edit instead store required fields into array of hashes. Made some minor cleanup along the way to methods edited in this commit.
- Changed view to use hashes to access data instead of AR Object.

https://bugzilla.redhat.com/show_bug.cgi?id=1114747
https://bugzilla.redhat.com/show_bug.cgi?id=1115652
Made suggested changes from PR review.

Removed code duplication from initial_setup_for_instances_form_vars method.

https://bugzilla.redhat.com/show_bug.cgi?id=1114747
https://bugzilla.redhat.com/show_bug.cgi?id=1115652
Remove @record from session and move grid xml from @edit to @temp

https://bugzilla.redhat.com/show_bug.cgi?id=1114747
https://bugzilla.redhat.com/show_bug.cgi?id=1115652
Changed to only save/update instance field if it's not nil.

Added a missing header column "On Error" in Instance grid, that was causing grid to display incorrect data in rows.

https://bugzilla.redhat.com/show_bug.cgi?id=1114747
https://bugzilla.redhat.com/show_bug.cgi?id=1115652
Merge pull request #139 from h-kataria/removed_ar_objects_from_ae_instance_editor

Made changes to instance add/edit code to remove AR Objects from @edit
Added Fog wrapper class for OpenStack access.

The Wrapper class implements a single connection object that provides
access to all OpenStack services for a given connection.
It performs higher-level functions and facilitates service and tenant access.

Its intended use is by fleecing and inventory collection clients, implementing
patterns common to both. These clients won't be modified until after current
outstanding pull requests are merged.
Rubocop cleanup.
Merge pull request #149 from roliveri/openstack_handle

Added Fog wrapper class for OpenStack access.