Upd: restrict_fontsize added to ui/util.

Also added internal utility class _Size, instances of which are used by
restrict_fontsize for comparison.
Upd: autofit_text added to ui/util

This function, in conjunction with restrict_fontsize, should resolve the
fixed-fontsize issue discussed in todo once implemented throughout the
app.
Upd: Resolve font-size issue in categoryscroll

Category names now automatically fit as many words onto a line as
possible, and rendered names are guaranteed to not exceed the size of
the category boxes.
Upd: Resolve font-size issue for gameboard

Fixed font-size issue, as described in todo, resolved for all text
(category names and amounts) in GameBoard. Also format fixes for
docstrings in ui/util.
Upd: Resolve font-size issue for rules in intro

See todo
Docs update: todo

Also fixed docstring formatting in podium.
Upd: Resolve font size issue for player names

See todo. Player names are now autofit, and can thus be arbitrary length
(unreasonable lengths will not be aesthetically pleasing, of course).
Upd: New sample category name

New longer name to demonstrate how longer names are fit/scaled.
Docs: Update todo and customization instructions

Instructions updated to reflect how certain attributes can now be
arbitrary-length.
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