Parsing and input processing:
- unify alignment, direction
- find libraries (e.g., from .pro)
- parse .kicad_wks
- on parse error, politely complain, don't terminate;
  convert abort / assert(0) to proper error indications

Data model:
- implement destructors
- check for memory leaks
- sheets appearing multiple times are parsed anew each time. Should we try
  to combine them ?

Visualization (dwg.c and such):
- glabel: build for "right" style, then rotate poly (like hlabel)
- show open pins / wires
- check remaining alignment / direction / rotation cases in switch statements
- support mirroring (and detect-complain if unexpected) [should be done now]
- pin shapes (inverted, clock, etc.)
- optionally display pin type
- record.c (bb_rot): implement bounding boxes for text
- nesting gfx in diff is a huge kludge, caused by global vars in gfx.c

Rendering:
- better text size guessing also for FIG
- consider switching to Hershey fonts (that's what eeschema uses, right ?)
  (goal: prevent font geometry from changing when scaling)
- support fonts attributes ?
- support line thickness ?
- ~ as overline (grep for ~ in out.fig)
- PDF TOC
- let user set PNG size [we have zoom level]
- return indication of whether diff found any differences
- in diff, pass only options understood by cairo_png
- find out why in Cairo PDF non-dashed lines disappear if CAIRO_LINE_CAP_ROUND

GUI:
- fonts grow beyond their bounding boxes when zooming in
- dragging can be slow. maybe reusing old content and only redrawing new
  will help ?

On-going:
- use Pango to support markup in overlay boxes:
  https://developer.gnome.org/pango/unstable/PangoMarkupFormat.html