June2014 release

Meant to complement https://github.com/manics/omero-pychrm/pull/30.
Includes changeset from https://github.com/wnd-charm/wnd-charm/pull/30.
I've implemented the traditional "ShuffleSplit" flavor or cross-validation for pure Pychrm for both classification and regression style problems.

- NewShuffleSplit to perform cross-validation.
- PerSampleStatistics renamed from PredictedValueAnalysis
- New module pychrm.ArtificialFeatureSets
- Unit tests for just about all new functionality
- BREAKING API change: is_valid() changed to isvalid