open_url() is suitable for use outside of a module environment.  Will
let us use open_url to do SSL cert verification in other, non-module
code.

and the test_win_copy integration tests that depend on the checksum
have been updated in this change too.

Handle when role_dependencies is None.

Fix KeyError which occurs when not-existing entry is tried to be removed.

Apply #10563 to stable-1.9

stable-1.9 branch

Conflicts:
	lib/ansible/utils/module_docs_fragments/openstack.py

We're being too strict - there is a third possibility, which is that a
user will have defined the OS_* environment variables and expect them to
pass through.

Conflicts:
	lib/ansible/module_utils/openstack.py
	lib/ansible/utils/module_docs_fragments/openstack.py
	v2/ansible/module_utils/openstack.py

made sequence more flexible, can handle descending and negative sequences and is skipped if start==end

correct unbound error in ec2.py's RDS code path

Fixes #10910

fixes #10891