Update to Rust 2018

See merge request redox-os/liner!21

Remove the global buffer and instead a context-specific one

See merge request redox-os/liner!20

Fix regression with non-empty line

See merge request redox-os/liner!19

Feature/complete bugs

See merge request redox-os/liner!12

Remove escape code 1049l

Closes #7

See merge request redox-os/liner!18

Fixes redox-os/liner#7

On prompt, exit to normal buffer and reenable cursor keys

See merge request !14

Move the generic typing from the Completer type to the on_event method

See merge request !17

Keymap should not own the editor

See merge request !16

💥 Merge the EventHandler and Completer interface

See merge request !15

This will reduce the hassle of dealing with lifetimes and makes it
possible to remove allocations when they are not needed

Ignore timestamps (lines starting with #)

Closes ion#833

See merge request redox-os/liner!13