Modified Features.h/cpp to use DynamicObjectArray.
Added static_cast to overide checking of converting CSGObjective* to CPreprocessor*.
Added back_ups of Features.
Modification of Features.h/cpp successful using DynamicObjectArray.
Modification of Features.h/cpp successful using DynamicObjectArray.

- Use CDynamicObjectArray * for Features.preproc
- Use DynamicArray* for Features.preprocessed
Merge branch 'master' of https://github.com/zhh210/shogun
Fixes #660: Hack to fix double-free (simply setting features to NULL).
lua52 fix
Merge branch 'featureshogun' of https://github.com/zhh210/shogun into featureshogun