vty-4.0.0: TODO

Minor:
- input parser uses similar interface to DisplayHandle. Derive instance from terminfo
- Improve input handling performance.
  - base off of haskeline input system. The haskeline input system appears to be excellent and
    satisfy all of Vty's input requirements. The current haskeline distribution does not appear to
    export the required modules. Either:
        0. Add the required exports to the haskeline distribution. 
            - fine for development but complicates the UI for production clients. Though, exposing
              the modules would only complicate the appearance of haskeline's interface. 
        1. Partition the backend of haskeline into a separate package usable by both vty and
        haskeline.
- use compact-string for character encoding handling
- xterm cursor foreground handling.
    - specific color?
    - reverse video?
    - auto?
- resolve gnome-terminal performance.
    - too much output per update? Diff the previous versus the requested to reduce?

Major:
- Remove size fields in resize constr