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

examples/pio/Makefile.am

@@ -16,9 +16,9 @@ AM_CPPFLAGS += -DUSE_MPI
 endif ENABLE_MPI
 AM_CFLAGS = $(MPI_C_INCLUDE)
 
-AM_FCFLAGS = $(FC_OPTINC)$(top_srcdir)/src $(MPI_FC_INCLUDE)
+AM_FCFLAGS = $(FC_OPTINC)$(top_builddir)/src $(FC_OPTINC)$(top_srcdir)/src $(MPI_FC_INCLUDE)
 if ENABLE_MPI
-AM_FCFLAGS += $(FC_DEFINE)USE_MPI
+AM_FCFLAGS += $(FC_DEFINE)USE_MPI $(YAXT_FC_MOD)
 endif ENABLE_MPI
 
 AM_LDFLAGS =
@@ -57,7 +57,4 @@ CXXCOMPILE = $(LIBTOOL) $(AM_V_lt) --tag=CXX $(AM_LIBTOOLFLAGS) \
         $(LIBTOOLFLAGS) --mode=compile $(CXX) -static $(DEFS) \
         $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
         $(AM_CXXFLAGS) $(CXXFLAGS)
-PPFCCOMPILE = $(LIBTOOL) $(AM_V_lt) --tag=FC $(AM_LIBTOOLFLAGS) \
-        $(LIBTOOLFLAGS) --mode=compile $(FC) -static $(DEFS) \
-        $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) \
-        $(AM_FCFLAGS) $(FCFLAGS)
+PPFCCOMPILE = $(FCCOMPILE)