Remove routes collection mappings

When using the routes mapper's collection to map from URLs to
python functions several additional URIs are created by
default: 'new', 'format' and 'edit', eg this URI

/v1/images/new

was accessible and would return a '500'.

/v1/images/detail.xxx

was accessible and a 'GET' to it would create a file called 'detail.xxx'
in the image cache directory (where 'xxx' is an arbitrary string).

Similar resources for image memberships existed.

Other collection URIs (for both the API and Registry) would return
unexpected behaviour.

Use explicit mappings rather than a 'collection' to remove
the superfluous resources.

Fixes bug 1185828.

Change-Id: I2f451f0208d43cdc83dcf58a41ea31359b18fcf2
Prevent '500' error when admin uses private marker

A 500 error was being raised when an admin tried to use the
id of a private image owned by another user as a marker.

Do not return 500 in these cases.

Also added appropriate test coverage.

Fixes bug 1172719.

Change-Id: If77d45c684dd7d4dda9eefd519fc3d36fc57e07a
Add missing Keystone settings to scrubber conf

The provided conf file for glance-scrubber was missing the auth settings
stanza required to make it work 'out of the box' in a Keystone environment
such as Devstack.

Also add the "Security Options" line just below for consistency with the
other configs.

Change-Id: I1182fd3a7a79c0f6aeb601d65c31e462fb3610bb
Merge "Add missing Keystone settings to scrubber conf"
Merge "Prevent '500' error when admin uses private marker"
Merge "Remove routes collection mappings"