GeorectifyCoverage fails to handle paths with spaces

GeorectifyCoverage constructs gdal_translate command lines as strings without any consideration of arguments such as filenames containing spaces that might require quoting.

For example, building with -Djava.io.tmpdir=target in a path with spaces fails:

Rather than trying to add argument quoting and then preserve it through String split and join operations, a better approach is pass arguments lists as List<String> and let ProcessBuilder do all the argument quoting. This is a more idiomatic use of ProcessBuilder.