Updating SimpleITK to 0.9.0.dev171

This update contains minor fixes in the 0.8 release branch along with
the addition of many ITK RLE LabelMap filters. Additionally it
contains a major refactoring of Statistics filters. Which includes the
removal of the MeasurementMap structure and the statistic procedural
methods.

The LabelMap functionality and new Statistics filters will form the
foundation of several planned projects during project week.

Dashboard:
http://open.cdash.org/index.php?project=SimpleITK&date=20140509

One failing test related to deleting command, during a command, prior
behavior was to call std::terminate. A patch in ITK fixes this issue.

This commit also contains an initial implementation of the
ImageRegistrationMethod which is still under development and unstable.