We need an ability to pass an empty string parameter, such as api.php?continue=&... -- this is especially critical with the new "continue" param that enables the simplified continue mode (empty string), or will be used in the subsequent api calls as a regular string returned from previous call.
Every string parameter should have a checkbox in front of the text field (to allign with the boolean parameters).
- User can set the checkbox to mean "send an empty string as value"
- Starting to type in the text field should automatically set the checkbox.
- Deleting text in the field would clear the checkbox.
- Clearing the checkbox should delete all text.