function jLoops = li_getsigloops(hSys, bLocal)
Checks for loops in system <hSys>. If <bLocal> is present and true, only checks top level diagram, no loops passing subsystem borders are recognised. Otherwise it is checked for any loop passing through <hSys> or any subordinate subsystem. Returns an array list of loops <jLoops>, each represented by an array list of the object handles of those objects making up the loop in signal flow order.