ENH: Handle the new Integer64 field type introduced in gdal 2.0. Add default case at the end of switches to avoid warnings

ENH: Remove the TestCapability() method from the proxy namespace, has it is only needed for the Delete() method and does not exist anymore in gdal 2.x. Improved Delete() method instead, and simplified OGRDataSourceWrapper and OGRVectorDataIO code accordingly.

ENH: Adding proper detection of gdal version >= 2.0 and report in configuration header. The class OGRVersionProxy serves as a proxy containing #if switches between gdal 1.x and gdal 2.x implementations

This reverts commit b741226d.

BUG: Fixing bug #983 (Split map was not correctly estimated when ImageRegion did not start at [0,0]). Added two tests for this case as well.

BUG: Fixing bug #983 (Split map was not correctly estimated when ImageRegion did not start at [0,0]). Added two tests for this case as well.

Following remarks from debian packagers, the ITCopyright.txt was mentioned in
several files but not available in the Copyright directory.  After contacting
the contributor Gregoire Mercier, he has suggested to harmonize the copyright for his
contributions.  Files with GET or IT copyright referenced now the
IMTCopyright.txt file (Institut Mines Telecom) which was added to the Copyright directory.

Moreover, Gregoire Mercier confirmed that he is not the author of 7 files which
are mentioning the GET or IT copyright:

Modules/Filtering/Projection/include/otbROIdataConversion.h
Modules/Filtering/Projection/include/otbROIdataConversion.txx
Modules/Segmentation/Conversion/test/otbVectorDataRasterizeFilter.cxx
Modules/Segmentation/Conversion/test/otbVectorDataToLabelImageFilterWithoutReader.cxx
Modules/Segmentation/Conversion/test/otbPolygonizationRasterizationTest.cxx
Modules/Segmentation/Conversion/test/otbVectorDataToLabelImageFilter.cxx
Modules/Segmentation/Conversion/test/otbOGRDataSourceToLabelImageFilter.cxx

Thus, the copyright was also modified for these 7 files (CNES Copyright).