Remove external AWS links and add doc if needed.

Closes bug #1252640

Change-Id: Ifae43c7ba457e8962360dd5b70cbb8b202365eee
Make engine service docstrings conform to Sphinx

This allows our Sphinx-generated documentation to render the
parameters correctly.

There were some errors in some of the "argN"-documented
functions, so I've updated them to include all the parameters.

Change-Id: Ic3b2c7702331bc85744b24434edbb2656c90916a
VersionNegotiation - 404 if no version is provided

The version negotiation middleware tries to identify the API version for
a specific url, and then perform routing. It also provides version info
if you attempt to reach "/versions". However, it also returns version
info if you attempt to reach any other endpoint that does not match a
version url.
The version negotiation middleware was modified in order to return all
the available versions of the api only when:
 1- No version is present in the URI and the Accept HTTP Header
 2- The request path is / or /versions
If the version is not provided and the request path is other than the
two mentioned earlier a 404 HTTP Code is returned.
If a version is provided the middleware strips the version from the URI and
pass the request to the next middleware/app.
Added a test suite to ensure that the Version Negotiation Middleware
work as expected.

Change-Id: I1dde1304de60533491790c33db7d2f74d3373722
Closes-Bug: #1251078
Remove duplicate test scenario

This is causing the gate to fail, maybe because of a new version
of testr.

Change-Id: Ice03d848118638f56f7df36ce08b3a68c371dd2c
Remove property decorator in TemplateResource

These methods can do quite a bit of work and treating
them as properties seems a bit odd.

Change-Id: I99cc3c9f74f59f9984daa3e128651926830e9d29
Merge "VersionNegotiation - 404 if no version is provided"
Merge "Make engine service docstrings conform to Sphinx"
Merge "Remove property decorator in TemplateResource"
Merge "Remove external AWS links and add doc if needed."