[AD] allegro 4.1.17/18 and allegrogl mouse

[<Xavier_Gonzalez@xxxxxxxxxx>]

Hi, the problem still persists (I reported it a while back, the mouse on 
windows on a windowed mode of an allegrogl program not being able to leave 
the client region if install_mouse was called and not showing the cursor 
when over the window if it wasnt), I tried to look into it myself but no 
luck :-/

Has anybody else looked into it? Thanks!