Renames vcs directory to controllers. Refs #52.
Implements capturing scroll wheel events. Refs #52.
Propagates scroll ticks to text field. Refs #52.
Uses dispatch to reset accumulated scrollwheel. Refs #52.
Moves view subclasses to subdirectory. Refs #52.

Also renames EHModify_view to EHChatty_view.
Documents scrollwheel feature. Updates changes log. Refs #52.
Merge branch 'feature/t52_cursor_keys_modify_dialog'