This commit is a major semver bump. Every progra utilizing escape codes generated by Termion is likely broken. The main change is to make each escape has their own type implementing the Display trait.

- Use formatters, mainly Display for escapes.

- Add Truecolor support (`color::Rgb`).

- Put each primitive into distinct modules.

- Add is_tty for checking if some stream is a TTY.

- Add multiple new examples.

Alternative fix for compilation on Redox

fix cursor moving

add move_cursor_{left,right} to TermWrite

Update README.md

Fix example reference

Refactor read_passwd

Undo color changes to test redox 256 color support

Get terminal size for Redox's kernel terminal

Use env for terminal size in redox

Line-reading logic is now in its own method

Fix redox support

Fix typo in doc

Fixed keys example