now only correct chart can be created in SFC Viewer

if user trying to connect incompatible blocks (by IEC 61131-3 standard), wire highlight will become red

{
    "url":"ws://127.0.0.1:8888",
    "realm":"Automation",
    "ID":"wamptest",
    "password":"1234567890",
    "key":"ABCDEFGHIJ"
}