I don't think warning level "None" was really doing the trick. Fixed that.

You can now customize the severities of all warnings, even 504 and 510.

When warning level is "None", scanning, i.e. lexical analysis, is faster.

source/org/thdl/tib/input/TibetanConverter.java

@@ -292,7 +292,8 @@ public class TibetanConverter implements FontConverterConstants {
                     = ACIPTshegBarScanner.scanStream(in, null,
                                                      ThdlOptions.getIntegerOption("thdl.most.errors.a.tibetan.acip.document.can.have",
                                                                                   1000 - 1),
-                                                     shortMessages);
+                                                     shortMessages,
+                                                     warningLevel);
                 if (null == al)
                     return 47;
                 boolean embeddedWarnings = (warningLevel != "None");