Give the Designer's .log file a real name

(I called this a Feature since it's been this way for years and we've not recorded it as a defect before. However, Bernd Groh pointed out this issue, so I'm recording it on his behalf.)

The MetaMatrix and Teiid Designers have always created a .log file in the .metadata directory. The name is not easy to find and is a nuisance to use (for example, when attaching the log file to an email message).

Please incorporate a "real" name, like "designer.log".