* add new addOptions option
* replace defaultOptions with addOptions for all extensions
* replace defaultOptions with addOptions for all demos
* replace defaultOptions with addOptions in docs
* refactoring
* refactoring
* drop object support for addOptions
* fix optional options
* fix tests
Currently drop cursor defaults to black rather than the text color, which is what normal carets default to. Using `currentcolor` should provide a better default value.