Upgrades GDAL and its dependencies to the latest version that still supports Python 2.

• Although the most recent versions of GDAL switched to cmake, these do not support Python 3. I didn't notice it at the beginning, and thus created a cmake config in one of the commits. I plan to squash these commits, but keep a copy of this branch in my fork, so we can recover that information if/when we move to Python 3.
• Switch from JasPer to OpenJPEG driver for JPEG 2000 support. Although JasPer is still supported in this version, support for it is removed in the latest versions of GDAL.
  • Question: Should JasPer be removed from SlapOS repo?
• Proj.4 was renamed to Proj and upgraded. It also switched to cmake.
• Geos was upgraded and also switched to cmake.
• Add support for RTree in Sqlite, as newest GDAL versions require it.

Test results apparently pass, but AFAIK they do not test GDAL behavior. I could make it compile in my KVM (in SUSE SLE 15 SP 6 Release Candidate) but I have not tested it yet (I don't even know if we have tests). I mention it just in case we want to delay the merge.