Bug 327558

In the list of functions, there is a checkbox to activate/deactivate the function in the render view. This checkbox only affects the view if the function is selected, too.

Reproducible: Always

Steps to Reproduce:
1. add 3 functions
2. try to remove the tick of a non-selected function
3. see that the function is still plotted
4. select the function (by clicking on its definition)
5. see that the tick in its checkbox re-appears
Actual Results:  
see 3. and 5.

Expected Results:  
3. function should disappear in the plot
5. the tick in the checkbox should always represent the render state, not just when selected