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

app/Makefile.am

@@ -35,3 +35,18 @@ clean-local: clean-local-dirs
 .PHONY: clean-local-dirs
 clean-local-dirs:
 	-rm -rf *.dSYM
+
+# overrides to make regular compilations also use libtool
+COMPILE = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
+        $(LIBTOOLFLAGS) --mode=compile $(CC) -static $(DEFS) \
+        $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
+        $(AM_CFLAGS) $(CFLAGS)
+FCCOMPILE = $(LIBTOOL) $(AM_V_lt) --tag=FC $(AM_LIBTOOLFLAGS) \
+        $(LIBTOOLFLAGS) --mode=compile $(FC) -static $(AM_FCFLAGS) $(FCFLAGS)
+LTCXXCOMPILE = $(LIBTOOL) $(AM_V_lt) --tag=CXX $(AM_LIBTOOLFLAGS) \
+        $(LIBTOOLFLAGS) --mode=compile $(CXX) -static $(DEFS) \
+        $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
+        $(AM_CXXFLAGS) $(CXXFLAGS)
+LINK = $(LIBTOOL) $(AM_V_lt) --tag=CC $(AM_LIBTOOLFLAGS) \
+	$(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \
+	$(AM_LDFLAGS) $(LDFLAGS) -o $@