[mkgmap-dev] rules test

Hi Gerd, I have been having difficulties with the mkgmap test code which uses the discontinued javax.xml.bind.DatatypeConverter for a single function printHexBinary. Despite downloading a copy of the library and telling Eclipse to use it, it doesn't seem to want to work. I found a replacement bit of code on the Internet, but as I can't compare the two outputs I can't confirm its output is identical. Can you take a look at the attached patch which does away with the dependency on javax and allows the tests to run under the latest version of Eclipse? Thanks, Mike