This patch does not clean up all warning from 'guix lint' because:

1. Warnings about patch names are generated in cases where a single
patch is used in several packages, or in packages that inherit from
another.

2. Many descriptions begin with the package name in lowercase form,
which triggers a warning about the description beginning with a
lowercase letter.  In this patch I capitalised the package name if I
could find a reference to the capital form on the package's home-page
somewhere.  Many packages are quite insistent that the package always be
referenced by the lowercase name, and I'm not sure how the description
would be reworded, or whether it really needs to be.  We could add an
exception to the description-starts-with-a-capital-letter rule for when
the package name is the first word.

3. Some synopses begin with a numeral, triggering the capital-letter
warning.

4. Handling the pkg-config warnings should really have the builds
tested.

5. I didn't really want to begin looking at the synopses and
descriptions in xorg.scm...

Comments welcome.  Nitpicks especially, since much of this is already
quite nitpicky. ;)