Fix TemplateResource list property conversion

In the convertion from "a,b,c" to ['a', 'b', 'c'] we are
not checking for the case of an empty list.

Change-Id: I834c4755abf33793a9484138f9dac97d7d8194da
Closes-bug: #1221009
Fix H233 in sphinx config

This is being flagged in local flake8 runs.

Change-Id: I99f05996711b3851811940ad5741e96d5ae61ed6
Run cfg.CONF.reset() on test cleanup

This means clear_override and clear_default do not
need to be called explicitly for each set_override and set_default
call.

This also fixes any potential test execution order issues
where an option has been set without being cleared at all.

Change-Id: Ic40c3be10b32eb3011bc0733cee9c1faaf8f1240
Fixes-Bug: #1221476
Merge "Fix H233 in sphinx config"
Merge "Run cfg.CONF.reset() on test cleanup"
Make the new template validation usable from tests

This is so we can assert that new TemplateResources expose the
api that we are expecting.

Partial-Bug: #1215797
Change-Id: I6273f6e046bb7bd5e075e9190d8011af976573b8
Make global TemplateResources usable in the tests

At the moment we need the templates installed into /etc/heat/templates
and this is not very nice for the tests. So this patch
replaces "/etc/heat/templates" with the project's own template
path so we can at least test the api of the template resources.

Partial-Bug: #1215797
Change-Id: Ie4924b0358b97af8feaad93ed9187976b8932e3d
Move dbinstance into a TemplateResource

The old dbinstance will soon be overtaken by the trove resource.
- The only reason for keeping this around is for people that don't
  have trove installed and want to use the AWS resource.
- Seperating it out into a TemplateResource really makes it easier
  for deployers and users to customise it.
- The old dbinstance did nothing "special" in python, and was really
  one of the first "TemplateResources" as it attempted to convert properties
  into parameters. Since this in now done a lot better in the TemplateResource
  lets just make use of that.

This will make it easier to migrate to other distros and versions.

Partial-Bug: #1215797
Change-Id: If72e1f40f67dc831551e0db8df8caaa002aaaeda
Change the dbinstance to F19

The current template is based on F17 which is eol.

Closes-Bug #1215797
Change-Id: I888fba67dc8412c8b57243d76b45494a6beb91c4