Add class denoting a token range.

Signed-off-by: Aron Cedercrantz <aron@cedercrantz.se>
Add arrays of tag and user token ranges.

Signed-off-by: Aron Cedercrantz <aron@cedercrantz.se>
Add a search bar accessory view.

Signed-off-by: Aron Cedercrantz <aron@cedercrantz.se>
Add a search bar input accessory view.

- Allows the user to tap a button to start searching for a tag or user.
- The actual rendering and addition of the tags have not yet been
implemented.

Signed-off-by: Aron Cedercrantz <aron@cedercrantz.se>