Enable gtk notebook scrolling so that the tab bar doesn't change the window size.
Set window size to default when unfullscreening.

This works around problems in xfwm4 where tabbing out of tilda (e.g. to change
desktop) when fullscreened will mean a subsequent unfullscreen won't restore the
dimensions of the window.
Merge pull request #27 from bnkr/unfullscreen-dimensions

Set window size to default when unfullscreening.
Merge pull request #26 from bnkr/tabs-are-too-long

Notebook is scrollable so long tab names don't break window size