Clarify the port value always defaults to 3306

debconf detail requirements and fix typos

Remove extra quote from the mysqldump password argument

ssh connection plugin: Make comments more verbose

Fix the default url of get_xml function.

Fixes #6800

Fixes #6822

Fixes #6806

debconf correctly quote strings

Also adds an integration test for authorized_key for future validation.

Fixes #6700

redhat_subscription calls AnsibleModule() without argument_spec

Fixed cwd for submodules update

Fixes #6455

Fix interpreter lines in a couple of modules

The Rhsm object requires an AnsibleModule but it isn't created with an argument_spec and fails.  Since the rhn.module is set directly after, setting None for the required argument of Rhsm fixes the module.

module_retention isn't defined anywhere, including the help.

While the [boto docs](https://github.com/boto/boto/blob/develop/boto/rds/__init__.py#L253) make it seem like the default value of `port` is changed depending on the engine chosen, AFAICT from looking at the code the default value is never changed from 3306.

I think the docs are intended to be read as "the default value used by <engine> is <port> so you should change `port` to that value".

If you don't specify the port value and chose the database engine as PostgreSQL you'll end up with a PostgreSQL instance running on port 3306.

The mysqldb Ansible module will fail if the state specified is import or dump with a '1045: Access Denied' mysql error for complex passwords.

This is caused by the extra quote around the '--password' argument to mysqldump, as pipes.quotes already quotes the password string.

>>> "--password='%s'" % pipes.quote('simple')
"--password='simple'"

>>> "--password='%s'" % pipes.quote('c0mplexp@ssword!')
"--password=''c0mplexp@ssword!''"

>>> "--password='%s'" % pipes.quote('password with space')
"--password=''password with space''"

Explain _communicate() more.

Disclosure policy should really be up here, so fixing that.

Fixes #6677

Related to f23bb344

Fixes #6657