lib/browser/GraphBrowser/ParseError.java

Cycle breaking in the bounds takes care of singly recursive datatypes, so we don't need to do it again;
the effect of removing the constraint varies on problem to problem, but it tends to be overwhelmingly negative in conjuction with the new datatype sym breaking stuff at high cardinalities

package GraphBrowser;

class ParseError extends Exception {
	public ParseError(String s) { super(s); }
}