The following vi command mode keys are not implemented:

^N - Move cursor down one line.
^P - Move cursor up one line.
^R - Redraw screen
(  - Move backward to beginning of sentence.
)  - Move forward to beginning of sentence.
{  - Move backwards to beginning of next paragraph.
}  - Move forward to beginning of next paragraph.
|  - Cursor is placed in that column if possible.
,  - Reverse of the last f F t or T command.
;  - Repeat the last f F t or T.
F  - Scan back for character.
S  - Change whole line. same as cc.
T  - Search backward on line for character.
Z  - Writes file and exits file session.
s  - Delete single character under cursor and enter input mode.
