Consolidation with CDI-PIO (develop)

Generally, this is !11 (merged) rebased onto the develop branch.

This is the first develop-based version accepted by the Buildbot of ICON: https://buildbot.dkrz.de/grid?branch=m300488/cdi-pio-2-integration

tests/Makefile.am

@@ -78,7 +78,7 @@ EXTRA_DIST = test_cdf_write.c test_cdf_read.c test_cksum_base
 AUTOMAKE_OPTIONS = color-tests
 #
 clean-local: clean-local-dirs
-	-rm -f *~ *.grb *.grb2 *.nc *.nc2 *.nc4 *.srv *.ext *.cksum *.ieg *.log
+	-rm -f *~ *.grb *.grb2 *.nc *.nc2 *.nc4 *.srv *.ext *.cksum *.ieg *.log *.stderr *.stdout
 
 .PHONY: clean-local-dirs
 clean-local-dirs: