- RifEclipseOutputFileTools::timeSteps: avoid integer division by zero when
the restart file has no INTEHEAD
- libecl ecl_grid: return NULL when the main EGRID grid cannot be created,
and skip NNCHEAD blocks that cannot be read
- libecl well_info: skip wells when the restart header cannot be read
- cvf::Frustum::isOutside: do not assert on an incomplete frustum, cull nothing
Fixes#14901.