close #30 (NPE at

winterwell.markdown.editors.LinkRule.evaluate(LinkRule.java:71));
RuleBasedScanner 	calls 	LinkRule.evaluate

change is just these lines:

			//+ preventing NPE (Non-standard link should not be below as comment above suggests) by Paul Verest
			if (fDelimiters == null) {
				scanner.unread();
				return Token.UNDEFINED;
			}