Improvements to SDM:

- Added a getAsLandmarks() to SdmLandmarkModel
- improved sdmLandmarkDetection
Minor changes to ImageIO and the landmarkEvaluation app

- Added a GatherMethod::SEPARATE_FOLDERS
- Added a SimpleModelLandmarkFormatParser to parse landmarks in the form
of [name x y]
- Working on landmarkEvaluation app
- Some minor general improvements