Add Evil (Extended VI Layer) Mode

[BombchuLink]

What do you want

An implementation of an Extended VI Layer (evil) mode in Cordless; Making modular modes, and changing applied shortcuts to match vi(m).

Why

Most Terminal programs that have UI built into them (especially ones built on Ncurses) use the vi(m) standard methods of navigation, such as h,j,k, and l for movement, as well as modular modes (Normal/Insert/Visual).

Having a terminal based program match the standards of how terminal programs are (nearly) universally ran would make the program much more accessible, and usable to people who are use to other terminal based programs.

Implementation hints

Make 'h' and 'l' move between server/channel/users/messages, and make j and k scroll up/down in each respective window, yy to copy a message, press 'i' to enter the message box so you can type a message, and ESC to go back into normal mode to move between server/channel/users/messages box, there are other things that could be added, such as a normal mode inside of the text box itself, and modifier keys, but that's a bit of a stretch, at least for now.

[Bios-Marcel]

Same issue: #140