Make redminelib easy for newcomers

[Elrond]

If people should help play/test redminelib, it would be nice, if
there would be some rough and simple steps to actually start
playing with it:

Could you add some rough notes to the README?


-  What dependencies should be installed in the system's python?
   (apt-get string would be super bonus)
-  What's needed to use redminelib "in tree", that is, withoug
   installing it? Nothing, just have ``PWD/redminelib`` somehow in the
   python path, probably by having ``.`` in it? Please give a quick
   one line note to that fact?
-  Have a simple cmdline script for people to get started.
   Something you give the base url of the redmine instance and a
   bugnumber and that outputs all the info it can extract from that
   bug?
-  Put something like this in the README: "For starters try the
   following command: python rml-get-all-bug-info.py 444"

You don't have to write lengthy stuff, just rough notes. They
should not distract you too long from doing actual coding. Just
enough so that lazy testers (like me!) can just git clone, skim
README, install deps and immediately start playing/testing.

[Will Kahn-Greene]

This isn't really a mediagoblin bug but rather a redminelib
bug--the two projects are separate.

I copied this into bug 13 in redminelib:
`https://github.com/willkg/redminelib/issues/13 <https://github.com/willkg/redminelib/issues/13>`_

I've implemented redminelib-cmd and updated the documentation so
that should cover the issues.

[Will Kahn-Greene]

The original url for this bug was ​http://bugs.foocorp.net/issues/617 .