Fix tests and add line select
Refactor BidirectionalIter to remove if blocks
Allow for cells tagged with WRAPLINE to continue expanding the selection
Reorganize config into structs
Add test coverage that callbacks are called
Cleanup mouse config
- Uses Duration type for ClickHandler::threshold
- Removes `action` property from ClickHandler--this can be added in a
backwards compatible way later on
- Renames ClickState::DblClick to DoubleClick
fixup! Cleanup mouse config
This uses the rustc-test crate, a copy of the standard test crate, to
dynamically create tests for each reference test. No need to remember to
update the macro, just add the directory to ref!