PHP Command Line Shell: Use ncurses to get key inputs and write shell text

This class can use ncurses to get key inputs and write text to the command line shell.

It can initialized the ncurses extension to use the current shell optionally using a given shell history file and outputting a given screen file.

The class provides functions to move the position of the cursor and display text on the screen.

Sub-classes may extend the base class to define how to handle the use of certain keys like return, tab or escape, so sub-classes can define the output to display the screen as result of actions triggered by those keys.