Upd: Prepare clues.txt for experiment

clues.txt now has one clue per line. I'm going to see how using
autofit_text looks for drawing clues. If it looks decent, this will be
the new format of clues.txt as clue customization will be significantly
simpler.
Upd: Fix how clues.txt read in GameData

See previous commit; _build_clues_from_file now reads clues as one line
per clue.
Revert "Upd: Fix how clues.txt read in GameData"

This reverts commit 70a63412a2c51ab97b4997ddb20020b714819f1a.
Upd: Font size issue resolved for clues.

See todo for problem description, changelist for more details about new
clues.txt implementation. Clue text is now guaranteed to fit in its
area. Clues with images now automatically scale image and clue text
accordingly. In an image clue, the image is guaranteed at least the
bottom third of the screen area, but this area can be larger with
shorter text.
Upd: New sample clues

Sample clues updated to reflect different ways of entering clues
(autofit vs manual line breaks).
Docs: Update to v0.9.3