%VERTCAT Vertical concatenation of datasets (object extension)
%
%    C = [A;B]
%
% The datasets A and B are vertically concatenated, i.e. the
% objects of B are added to the dataset A. This is possible if
% the labels of B are given in a similar way as those of A.
% If new labels (i.e. classes) are added, the PRIOR field of
% A is cleared.
%
% If A and B have multiple label sets, they should have the same 
% names for the label lists (see ADDLABELS) and the above should hold
% for each label set separately.
%
% In addition it is required that the object descriptions given in
% the IDENT field have the same subfields.
%
% If B is not a dataset, empty labels are generated.
%
% The new objects are checked for the feature domains.
%
% See also SETLABELS, TESTFEATDOM