WIP - Image to image registration

This branch contains a few modifications to allow image to image registration, based on LSD detection and filtering.

The main modifications are :

• the filtering of the input DB can now handle independent segments (LINE/MULTILINE), as well as polygons
• the main application provides the transformation (output.idx/idy) as an output
• a new python script launches LSD on a reference and an alternative image, and computes the best transformation that aligns the alternative image onto the reference image.
• a very simple script (ApplyTranslation.py) can apply a new geotransform, including the translation, to an image. For python compatibily issues (between GDAL and OTB), the corresponding function cannot be called from the main script.

This has been tested on a few examples, but there are still some modifications to achieve :

• maybe we could have only a generic filtering function, that takes as input a vector file (mask file)
• the image to image registration may need some resampling instead of modifying the geotransform origin, in case users want to register images that are in their raw geometry (not georeferenced).
• ... (WIP)

This MR will close #2 and #3