Don't crash on bad files present in IG, ignore & warn instead

org.hl7.fhir.validation/src/main/java/org/hl7/fhir/r5/validation/ValidationEngine.java

@@ -736,7 +736,7 @@ public class ValidationEngine {
             throw new Exception("Unsupported version "+version);
 
         } catch (Exception e) {
-          throw new Exception("Error parsing "+fn+": "+e.getMessage(), e);
+          System.out.println(" - ignored due to error: "+e.getMessage());
         }
         if (r != null) {
           context.cacheResource(r);