cmake: Add check for gdal >= 2.0 and qcustomplot >= 2.0
cmake currently accepts gdal versions <2.0 which don't compile with Met.3D. Add a check for >2.0 Same for qcustomplot
Edited by Marc R.
cmake currently accepts gdal versions <2.0 which don't compile with Met.3D. Add a check for >2.0 Same for qcustomplot