Update header and stub library

* Update API to MPI 4.1
* Set VERSION.SUBVERSION to 4.2
* Remove MPI_Handler_function (gone since MPI 3.0)
* Sort all P?(MPI|MPI_T) routines by name
* Improve Makefiles

Author: dalcinl

Makefile

@@ -0,0 +1,4 @@
+all:
+	$(MAKE) -C lib $@
+clean:
+	$(MAKE) -C lib $@

README.md

@@ -1,2 +1,3 @@
 # header_and_stub_library
-The reference for the MPI standard ABI instantiated in mpi.h and a stub library libmpiabi.so
+
+The reference for the MPI standard ABI instantiated in mpi.h and a stub library libmpi_abi.so

include/mpi.h

@@ -1,18 +1,21 @@
-CC = cc
+CFLAGS = -Wall -Wextra -Wno-unused-parameter -pedantic
 CPPFLAGS = -I../include
-CFLAGS = -Wall $(CPPFLAGS)
 
-all: libmpiabi.a libmpiabi.so
+LN = ln -f
+LN_S = $(LN) -s
+RANLIB = ranlib
 
-libmpiabi.a: libmpiabi_stubs.o
-	ar -r $@ $^
+all: libmpi_abi.a libmpi_abi.so
 
-libmpiabi.so: libmpiabi_stubs.o
-	$(CC) -shared $^ -o $@
+libmpi_abi.a: mpistubs.o
+	$(AR) -r $@ $^
+	$(RANLIB) $@
 
-libmpiabi_stubs.o: libmpiabi_stubs.c
-	$(CC) $(CFLAGS) -c $^ -o $@
+libmpi_abi.so.0: mpistubs.o
+	$(LINK.c) -shared -Wl,-soname=$@ $^ -o $@
 
-clean:
-	-rm -f libmpiabi.a libmpiabi.so libmpiabi_stubs.o
+libmpi_abi.so: libmpi_abi.so.0
+	$(LN_S) $< $@
 
+clean:
+	-$(RM) libmpi_abi.a libmpi_abi.so.0 libmpi_abi.so mpistubs.o