Adds `css/spniDialogueUtilities.css`, which adds common utility classes
for dialogue formatting, as well as examples to use for character creators
to work from when writing their own CSS stylesheets.

Autodetection of creator names isn't (and will never be) perfect.
Character creators are listed in inconsistent formats and different spellings, etc.
But this gets 95% of cases right, and in all other cases you can just type in a (partial) creator name yourself to get it right.

(also cuts the old Credits modal)

1. localStorage is used instead of a cookie. Multiple entries are used, and keys have a prefix to avoid any collisions when hosted on other sites.

2. The existing cookie is converted so as not to lose unlocked endings in particular. This code can be dropped some time in the future.

3. Option values are handled and stored as-is intead of as opaque indices from 1 and up. For time values, this has the disadvantage that if we modify what e.g. "Slow" means, the old value will still be used until the user chooses a new option, but the advantages that we can later add more options or change the input elements to sliders without problems, plus the disadvantage can also be an advantage. Above all, there's no conversion back and forth and default values aren't specified in three or four places.

4. Option change event handles are attached with jQuery and the option values stored in attributes.

5. Backgrounds are renamed and moved to a subdirectory (that could have been done anyway; it's not a direct result of 3).

6. Clothes selections are stored as arrays of article names instead of 18 true/false values.

7. No separate askedUsageTracking flag. If no usageTracking value is in localStorage, then we haven't asked. Similarily, null is used for FORFEIT_DELAY and ENDING_DELAY to represent Disabled.

Emphasized the Help/FAQ button on the title screen by making it bigger and brighter.
Added a "last update time" indicator to the version button.

This switches the FAQ screen to using `display:flex`.
Furthermore, all modals have a `max-height` of `90vh`.