spring patch

* The pySPACE live interface has been largely improved.
* Documentation has been improved. (e.g., tutorials, data types)
* The YAML-Python syntax mapping has been improved.
* Numerous bugfixes and minor enhancements were performed (e.g., mpi backend, SOR SVM, wrong sorting in splitter nodes, loading of BCI datasets, customized node loading, feature normalization, sensor selection, ...)
* The code layout has been partially improved (live, datasets, incremental training, ).