Added docs and project management tool update

doc/files/activecanvas.txt

@@ -2,3 +2,21 @@
 #header function ActiveCanvas()
 
 
+Returns the canvas that drawing commands are currently applied to
+
+#code
+c1 = OpenCanvas(640, 480, 0, 0, 640, 480, 0)
+c2 = OpenCanvas(640, 480, 0, 0, 640, 480, 0)
+
+Canvas(c1)
+
+If ActiveCanvas() = c1 Then
+	Print "Active canvas is c1"
+End If
+
+Canvas(c2)
+
+If ActiveCanvas() = c2 Then
+	Print "Active canvas is now c2"
+End If
+#/code