Update Unit1.pas to ver2.0

Описание исправлений:
55   StrtoInt заменена на(==) StrToFloat
57   StrtoInt ==   StrToFloat
59   <=       ==   >=
80   y2 := ExecFX(x1) ==  y2 := ExecFX(x2);
88   added  d1 := d2;
124  added  Chart1.Visible:=true;