Forms do not flush keyboard responses

[smathot]

When you have a sketchpad with a certain duration that is followed by a form_text_input, pressing a key during the sketchpad presentation will result in direct input to the form_text_input. Oddly, this only happens if you press a single key. This should be fixed such that, by default, forms flush the keyboard and mouse buffer when they are shown.

[eort]

Oddly, this only happens if you press a single key.

When I tried that yesterday, it happened also with a series of key presses. They all appeared once the form started.