theme: Remove test screens
libtorc-baseui: Make theme signal/slot references relative

- themes no longer need to give fully qualified widget names for
signals/slots

- absolute widget references are now prefixed with a forward slash e.g.
/rootwindow
- to reference the widget parent use ..
- to reference the grandparent use ../..
- to reference a sibling use ../sibling
etc

- children/grandchildren etc should be referenced directly.