Really making fonts awesome in Fedora 21

[Pádraig Brady]

I was surprised at the blurriness of the _default_ font (Cantarell) on my new F21 install.

There were noticeable artefacts as well as general blurriness
with no noticeable difference between grayscale and rgba antialiasing.
Even worse was different text heights for bold and normal which
was immediately evident with text jumping around as I traversed
my thunderbird unread message list.

I used gnome-tweak-tool to change all Cantarell to Sans and the
experience was _much_ better. BTW size 10 was much better proportioned
on my 1920x1080 screen, than the default size of 11.

I went digging on the Cantarell issue and it seems to be
the only one affected due to the CFF renderer in freetype >= 2.5
  https://bugzilla.redhat.com/show_bug.cgi?id=1035486

You can change most of the default fonts with gnome-tweak-tool
though the setting for the default font must be manually edited as per:
  http://rlog.rgtti.com/2012/01/29/how-to-modify-a-gnome-shell-theme/

Note also that chrome seems to honour GTK2 settings only:
  https://code.google.com/p/chromium/issues/detail?id=375824

So while issues can be worked around, it's awkward
and the default experience should be getter IMHO.

Pádraig.