Decide baseline vertical position according to font metrics, instead
of the hardcoded 0.7 (in textwidget, which made the text a little
bit up in its box), and 0.75 (in toggleswitch, which made the text a
little bit down in its box). This usually gives a value around 0.72
or 0.73 with our ui fonts, which looks about right.
ReaderFooter: add bottom padding, now that our text goes a few pixels lower