added more special keys

Created by: IGI-111

This should partly solve #16

Key now supports Home, End, PageUp, PageDown, Delete, Insert and Function keys. All this is done through the detection of both VT100 escape codes and more modern standard counterparts. For instance, F2 can be both ESC OQ on VT100, screen, and some versions of xterm and ESC [12~ on rxvt and other xterm versions depending on your terminal.

Note also that only F1 through F12 are supported since codes tend to wildly diverge beyond that point and it's not part of the ISO or ANSI keyboard specs anyways.

Created by: ticki

For instance, F2 can be both ESC OQ on VT100, screen, and some versions of xterm and ESC [12~ on rxvt and other xterm versions depending on your terminal.

Could you add this to the docs of F2?

Created by: ticki

Very nice!