add fonts.scale and fonts.dir files for `xset +fp`

The fonts.scale files were generated by running `mkfontscale ./**/` and
the fonts.dir files were generated by running `mkfontdir ./**/` in this
Git repository's working tree.  Run those commands again to regenerate.

These generated files let you register their corresponding True Type
fonts with the `xset +fp` command, which "installs" them under Linux.
For example, you would do this by running the following commands if you
cloned this Git repository to your ~/.fonts/powerline-fonts/ directory:

```sh
xset +fp ~/.fonts/powerline-fonts/AnonymousPro
xset +fp ~/.fonts/powerline-fonts/DejaVuSansMono
xset +fp ~/.fonts/powerline-fonts/DroidSansMono
xset +fp ~/.fonts/powerline-fonts/InconsolataDz
xset +fp ~/.fonts/powerline-fonts/Inconsolata
xset +fp ~/.fonts/powerline-fonts/LiberationMono
xset +fp ~/.fonts/powerline-fonts/Meslo
xset +fp ~/.fonts/powerline-fonts/SourceCodePro
xset +fp ~/.fonts/powerline-fonts/Terminus/BDF
xset +fp ~/.fonts/powerline-fonts/Terminus/PCF
xset +fp ~/.fonts/powerline-fonts/UbuntuMono
xset fp rehash
```