Support non-smoothed bitmaps in Graphics fills, too

Doesn't work in Firefox yet, but that's a platform bug
Adds .height field to font metrics

We need this value lots of times, so it makes sense to precalculate it
Refactor TextField text run collection for cleanness and store more measurement data

Required for scrolling and `getLineMetrics`
Properly set and interpret default values in TextFormat
Preliminary real implementation of TextField#getLineMetrics()
Fixes bug in applying font from TextFormat
Fixes to calculation of TextField line metrics