save current listbox in all cases.
mask compatible with library links.
enhance image light not to hide input and output port labels drawn on top of these block icons.
disable inputs/outputs draw commands to avoid warnings when the number of inputs/ouputs is modified.
constant cleanup.
replace custom block by the library one.
replace block by the library one.
do not attempt to close the network object if it was not correctly opened.
Start function is called only once, InitializeConditions might open communication channel multiple times.