expPanelFun should be a fullpath

[k1o0]

Describe the bug
Currently expPanelFun (added by inferParameters) is just the name. If there is a panel of the same name in the path, that one is loaded, instead of the one in the folder of your expDef. Also fileFunction should be used in case the panel isn't on the path:

Rigbox/+eui/ExpPanel.m

Lines 138 to 141 in cd888f0

	% FIXME This should be done with fileFunction and this use of which
	% may not work on newer versions of MATLAB
	if isempty(which(params.Struct.expPanelFun)); addpath(fileparts(params.Struct.defFunction)); end
	p = feval(params.Struct.expPanelFun, parent, ref, params, logEntry);

Expected behavior
Should be a full path to ensure the correct panel class is instantiated.