Publish images to glance

This creates a new glance distributor as well as changes to pulp-admin.
Configuration of the distributor is done at repo creation time via command-line
arguments for now.

If an image already exists in glance, it is skipped. Images are correlated
between glance and pulp via image checksum and repo names. Additional metadata
is added to the image file in glance to make it easy for pulp to find.
doc_check updates

doc checker now checks for ":type  PARAM:" in addition to ":param PARAM:".

Note that there are two spaces after "type" so it lines up with "param" in code
blocks.
add doc check for return and return type

If a return statement is in a function, ensure  the function has :return: and
:rtype: in the docstring.
Merge pull request #11 from beav/glance

Publish images to glance