On OS X, pressing the command key while a Choices select is focused
will add the text "meta". While looking into the details, I found
quite a few more errors surrounding the "first keypress" behavior.
When a closed select is focused, the following things generate
incorrect behavior:
- Any key while shift was previously held: the first character
is incorrectly capitalized/lowercased
- If the keypress begins a "compose" input (e.g. option+` on mac)
the value will be "dead"
- Various other non-printable keys also emit output, such as
the arrow keys, media keys, etc.
Fix the entire category of behavior by better evaluating what
counts as a "printable" character.
