## Description of change
Three bugs:
* Some keys are IME-dependent. Right Alt can be IME mode switch for
Japanese / Korean, and Right Ctrl is often the Kanji button.
* If you press modifiers like Ctrl during bind-many-naive, it will skip
over a button, because of broken for loop logic that ends up calling
`inc_buttons_many_index` too many times
* trying to cancel out of bind-many-naive with left and right mouse
buttons swap doesn't work
## Testing
Validating various IME. I don't have a keyboard in another language
though..
## Link to GitHub Issue, if one exists
n/a
## Description of change
Improper bounds check resulting in crash when binding mouse buttons
beyond Mouse 5.
## Testing
Tested with `Edit` function.
## Link to GitHub Issue, if one exists
Fixes#139
## Description of change
Add an option for detecting window focus when accepting input.
The new default will be to have the following:
* naive bindings will check for window focus
* rawinput binds are not affected, will continue to be accepted
regardless of focus
Other options (always / never choices) can be picked by the user to
tweak the behavior if needed.
Clean up usage of `0xff` constant to represent invalid naive vkey.
## Testing
Still in progress, especially in regards to performance.
On a i7-9700 system, 10000 calls to `superexit::has_focus()` takes
250-350 microseconds, so this should not be a big deal at all.
bicarus