Remove ctl-l, plus commentary and pretty-printing
added commentary regarding page filename lookup alternatives
Change some names of cursor-positioning methods.
Reorg & reorder key definitions for clarity & efficiency
Set up default font size constant and use it
implement the scale() method also use default size constant
Add save_font_size method
Commentary
fiddle with key defs for editor
Use global constant for point size, other commentary
make key lists into sets for faster lookup
Zoom keys working and tested. Bookmark keys pending.
fix silly typos in scale()