Log a message when image object not found in swift

We should log when a request for an image object in swift returns a 404.

Fix for bug 1227786.

Change-Id: I27a970840cf448196245ba1e58523b9e0b1495f5
Cleanup and make HACKING.rst DRYer

Reference the OpenStack hacking guide in HACKING.rst and remove
duplicate entries. Adds placeholder section for glance specific
rules.

Change-Id: I1bfff8c69c9370e2d648197b7e71e229695ef627
Remove lxml requirement

Fixes bug 1252344

Change-Id: Iaa10b7c78bf03b00c84a27592265bb79203df376
Adding an image status transition diagram for dev doc

Now there is no image status transition diagram in the dev
doc, this patch will add one and keep the image source as
a dot file so that it can be updated easily in the future.
See http://www.graphviz.org to get more info about .dot file.

Fixes bug 1244995

Change-Id: I076c461f688be93eab8d3d1fa541990d7b79da5e
Add upload policy for glance v2 api

Related to bug 1250918

There currently exists no check in set_data function for glance
api v2 in the policy layer. This patch adds upload_image policy.

DocImpact

Change-Id: Ibccc78f8bccff3baa5aca574cf17bd14c5403ca2
Merge "Cleanup and make HACKING.rst DRYer"
Merge "Log a message when image object not found in swift"
Merge "Add upload policy for glance v2 api"
Merge "Adding an image status transition diagram for dev doc"
Merge "Remove lxml requirement"