Add WordPress example using software config

This patch adds two HOT example templates for WordPress using the new
software config feature added in Heat Icehouse.

The actual config scripts are provided as separate files that get
included into the templates using get_file.

There is one template to deploy WordPress on a single server, and
another template to deploy it on two servers. Both templates use
the same config scripts.

The templates have been tested with a Fedora 20 based image that
had image builder elements required for software config built in
(as described in a README in one of Steve Baker's pending changes
https://review.openstack.org/#/c/84910 ).

I based the scripts on a pending change by Mike Spreitzer, so thanks
to him as well: https://review.openstack.org/#/c/88523

Change-Id: I63d8945fcb619b406093595073242a25bbb66387
Merge "Add WordPress example using software config"