Fix glitches when dragging content caused by the drop indicator receiving mouse events.
Make Control-drag work on Firefox.
Make clicking or selection-dragging at the end of a wrapped line select the right position.
show-hint addon: Prevent widget scrollbar from hiding part of the hint text.
rulers addon: Prevent rulers from forcing a horizontal editor scrollbar.
search addon: Automatically bind search-related keys in persistent dialog.
sublime keymap: Add a multi-cursor aware smart backspace binding.