Scale space tool

Two tools to display curvature behavior at different scales, like for instance command:
./estimators/curvatureScaleSpaceBCC -f ${DGtal}/examples/samples/contourS.fc --gridStepInit 0.001 --gridStepIncrement  0.0005 --gridStepFinal 0.05 -o cssResu.png
will produce this result:
![cssresubcc](https://cloud.githubusercontent.com/assets/772865/2646108/f515b0a2-bf39-11e3-96f8-c7606173f43b.png)
or with IIM:
 ./estimators/curvatureScaleSpaceIIM -f ${DGtal}/examples/samples/contourS.fc  --radiusInit 2 --radiusIncrement 0.5 --radiusFinal 50 -o cssResuIMM.ppm  -c 1

![cssresuimm](https://cloud.githubusercontent.com/assets/772865/2646147/5d2912ce-bf3a-11e3-95b6-13eaa36f384a.png)