Change update-deb-sources to more general name.

We will be modifying `update-repos` to be a package that can control the
sources and update the package lists for a variety of distributions.

We will start with debian and ubuntu, using facter to distinguish
between them.
Made update-repos a general module.

This module currently supports Debian and Ubuntu, but the framework is
there to easily add support for other distributions.
Updated some of the github-clone docs formatting.
Added a $name parameter, controls repo-dir name.

This parameter allows changing the name of the directory the project
will be cloned into (which defaults to the project name).
Finished emacs module, fixed bugs in git, update.

The emacs version can now successfully install emacs and download a
emacs configuration from github, putting it in ~/.emacs.d.

The bug fixes are fairly numerous.

  1) In the `git` module, we now insure that git is installed when
     trying to call `git::github-clone`.

  2) Adding the `$name` parameter in the the `git::github-clone`
     definition introduced a bug where if that directory existed, the
     code would exit successfully without cloning the repo. This bug
     has been fixed.

  3) In the `update-repos` module there was a bug with how the
     `$disto` variable was being used, this is fixed.

  4) The `update-repos` module no longer incorrectly warns that you're
     installing debian sources.list in ubuntu and vice versa.

Note: The solution to bug (2) is to delete the directory under `$name`
if it exists, which is somewhat reasonable. However, a better solution
might be to fail if this directory already exists.

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