From within the revision graph window, the default tag filters from the settings dialog can
be overridden. If tags are set to be shown inside the revision graph nodes, then they
can be filtered based on a regular expression. The filter can be either to include or
exclude the tags that match the filter based on the show/hide toggle. For proper
regular expression syntax, see
http://java.sun.com/javase/6/docs/api/java/util/regex/Pattern.html