store plugins directly in $libdir

instead of $libdir/plugins. We have no other binary components.

Makefile.in

@@ -207,7 +207,7 @@ clean::
 
 install_no_local::
 	mkdir -p $(BINDIR)
-	mkdir -p $(LIBDIR)/why3/plugins
+	mkdir -p $(LIBDIR)/why3
 	mkdir -p $(DATADIR)/why3/images
 	mkdir -p $(DATADIR)/why3/emacs
 	mkdir -p $(DATADIR)/why3/lang
@@ -691,7 +691,7 @@ plugins/whytptp.cmo: $(TPTPCMO)
 	    $(OCAMLC) $(BFLAGS) -pack -o $@ $^
 
 install_no_local::
-	cp -f plugins/whytptp.cm* $(LIBDIR)/why3/plugins
+	cp -f plugins/whytptp.cm* $(LIBDIR)/why3/
 
 # depend and clean targets
 
@@ -727,7 +727,7 @@ clean::
 	rm -f bin/why3-cpulimit src/tools/*~
 
 install_no_local::
-	cp -f bin/why3-cpulimit $(BINDIR)
+	cp -f bin/why3-cpulimit $(BINDIR)/why3-cpulimit
 
 #########
 # why3doc

src/config.sh.in

@@ -8,7 +8,7 @@ localdir="None"
 plugins="false"
 
 if [ "@enable_local@" = "yes" ]; then
-    libdir="@LOCALDIR@"
+    libdir="@LOCALDIR@/plugins"
     datadir="@LOCALDIR@/share"
     localdir="Some \"@LOCALDIR@\""
 fi

src/driver/whyconf.ml

@@ -109,7 +109,7 @@ let add_plugin m p =
   then m
   else { m with plugins = List.rev (p::(List.rev m.plugins))}
 
-let pluginsdir m = Filename.concat m.libdir "plugins"
+let pluginsdir m = m.libdir
 let load_plugins m =
   let load x =
     try Plugin.load x