Rename nova.compute.instance_types to flavors

First step in removing references to instance_types. Rename instnace_types.py
and update references to it. We currently use instance_type and flavor as
synonyms, to reduce confusion we are picking one. We are going with our own
terminology, flavors.

renamed:    nova/compute/instance_types.py -> nova/compute/flavors.py

Partially implements bp flavor-instance-type-dedup

Change-Id: I9dc04cf311aa8813be4f5329f23729d2c43cae6d
Fixes mock calls in Hyper-V test method

Fixes bug: #1177605

This patch adds missing mocked calls to the test method
test_spawn_nova_net_vif_no_vswitch_exception implementation.

Change-Id: I115e2e081ef1273c78de1bba1414002d30eaa574
Merge "Fixes mock calls in Hyper-V test method"
Session cleanup for db.floating_ip_* methods

Session objects shouldn't be used in public db.api methods
because db.api should be independent of db implementation.

Remove session parameter from:
  floating_ip_create
  floating_ip_get_by_fixed_ip_id

I didn't remove session parameter from floating_ip_count_by_project
because it causes changes in nova.quota. So it will be done in
separated patch.

Cleanup test for floating_ip_count_by_project removed 3rd
parameter (it should be session, but it is not required).

blueprint db-session-cleanup

Change-Id: Ifdf9edb17746a8e5b486317c917ea69016a2b99d
Remove insecure default for signing_dir option.

The sample api-paste.ini file included an insecure value for the
signing_dir option for the keystone authtoken middleware.  Comment out
the option so that we just rely on the default behavior by default.

Fix bug 1174608.

Change-Id: I6189788953d789c34456bbe150b8ed6ce6f68403
Merge "Rename nova.compute.instance_types to flavors"
Merge "Remove insecure default for signing_dir option."
Removes duplicate assertEqual

Removes duplicate assertEquals in "test_snapshot_in_ami_format"
that evaluates the image state.

bug #1177948

Change-Id: I380bc9596cae698c1b99d1bbfbdb98705fd938b5
Merge "Session cleanup for db.floating_ip_* methods"
Merge "Removes duplicate assertEqual"