[MEDIUM] implement memory pools version 2

The new pools know about their size and usage. Malloc is not used
anymore, instead a dedicated function to refill the entries is used.
diff --git a/Makefile b/Makefile
index c7017e5..122f1c6 100644
--- a/Makefile
+++ b/Makefile
@@ -217,7 +217,7 @@
        src/time.o src/fd.o src/regex.o src/cfgparse.o src/server.o \
        src/checks.o src/queue.o src/capture.o src/client.o src/proxy.o \
        src/proto_http.o src/stream_sock.o src/appsession.o src/backend.o \
-       src/session.o src/hdr_idx.o src/ev_select.o src/acl.o
+       src/session.o src/hdr_idx.o src/ev_select.o src/acl.o src/memory.o
 
 haproxy: $(OBJS) $(OPT_OBJS)
 	$(LD) $(LDFLAGS) -o $@ $^ $(LIBS)