Debugged TaskOperationFeatures featurs reporter. The feature reporter
reports the effects of individual task operations on every residue in a
pose. The effects of a feature reporter on a residue are whether the
residue becomes packable or designable due to the task operation.
The bug was that parse_my_tag had a subtly incorrect signature and the
the parse_my_tag of the FeaturesReporter base class was being called.
The new version of the feature reporter inherits from MetaWidget as a
method of inserting itself into the registrator/creator system rathter
than having an explicit regristrator and creator.