v0.2.1: this version start a white window correctly
input: disable the input
display: use PILOT_CREATE_THIZ macro
widget: first new implementation
canvas: the first widget
list: foreach allows to add unspecified arguments to the function callback
window: allows paint buffer video directly inside the main thread or by multi threading

 if the redraw callback of a widget return different of 0, the window force the redraw when the surface is ready
 if the redraw callback returns 0, the application considers that the window is refresh and it's a new event that will request the redraw, or a thread
blit: the new object request the pixel format
debug: remove useless traces
form, timer: features useles at this point
theme: new window theme support
input: new keyboard and pointer support

only focused widget can intercept key events
the window look for the default focussed widget at the enter. After the click inside a widget focus another widget.