Fix invalid read_deleted value in _validate_unique_server_name()

read_deleted passed to model_query() may have the value 'yes', 'no',
or 'only', but was being passed the value False. The implementation of
model_query caused this to be ignored, and the value of
context.read_deleted used instead.

This change cleans up kwarg parsing in model_query to ensure that all
values explicitly passed in retain their given value, unless they were
explicitly set to None, in which case they are defaulted anyway.  This
last is the expectation of current callers of model_query().

Changes Exception thrown for invalid values to ValueError.

Change-Id: I2d1bbdbd4a391ad3487da905df2e812166a837de
replace httplib.HTTPSConnection in EC2KeystoneAuth

httplib.HTTPSConnection is known to not verify SSL certificates
in Python 2.x. This change replaces use of httplib.HTTPSConnection
with the requests module. It imports config settings related to SSL
verification: ssl.key_file, ssl.cert_file, and ssl.ca_file. It also
adds one config setting: keystone_ec2_insecure. By default, SSL
verification is on, but can be disabled by setting:

keystone_ec2_insecure=true

This patch is based on the keystone middleware ec2 token patch:

https://review.openstack.org/#/c/76476

SecurityImpact
DocImpact
Closes-Bug: #1373992

Change-Id: I8e46d41164e9478b820cad569ba82f25de244620
VMware: clean up unit tests

Remove unnecessary test class

The patch also removes duplicate test methods. These were duplicated
due to the fact that there were two drivers (ESX and VC). Now we
only have the VC driver.

TrivialFix

Change-Id: Idd0f6848ca05e0793506471bb226e2c3530df8be
virt: use instance object for attach in block_device

It will be better if we'll use `instance` like object.

Change-Id: I56b3931da7339d2d350a7d1368dd39c7e398d3e6
Merge "Fix invalid read_deleted value in _validate_unique_server_name()"
Merge "VMware: clean up unit tests"
Merge "replace httplib.HTTPSConnection in EC2KeystoneAuth"
Merge "virt: use instance object for attach in block_device"