Fan speed doesn't capture last existing fan speed when change happens over more than 1 layer

[randyinla]

When a fan speed change occurs on 1 layer, the script is able to capture any existing fan speed changes in that layer (M106 or M107) and reset the GCode to that fan speed at the end of the layer change. However, when the change is to occur across more than 1 layer, the script does not look for the latest fan speed change so does not reset the fan speed correctly at the end of the last layer change.

When the speed change is spread across more than 1 layer, the script should scan for fan speed changes on every layer, always storing the latest one it finds until the endLayer. Then it should reset the GCode to that numer at the end of the endLayer.