Patch Makefiles for --as-needed and properly install into DESTDIR

--- ./Makefile

+++ ./Makefile

@@ -11,6 +11,7 @@ clean:

 install:

 	@echo "Installing vnStat..."

+	install -d $(BIN) $(MAN)/man1 $(CRON) $(DESTDIR)/var/lib/vnstat

 # move some really old version database(s) if found

 	@if [ -d $(DESTDIR)/var/spool/vnstat ]; \

@@ -41,7 +42,6 @@ install:

 	then install -m 644 cfg/vnstat.conf $(DESTDIR)/etc; \

 	fi

-	install -d $(BIN) $(MAN)/man1 $(CRON) $(DESTDIR)/var/lib/vnstat

 	install -s -m 755 src/vnstat $(BIN)

 # update man page, gzip it if previous version was done so	

--- ./src/Makefile

+++ ./src/Makefile

@@ -5,7 +5,7 @@ OBJS = ifinfo.o db.o dbaccess.o misc.o cfg.o

 default: vnstat

 vnstat: $(OBJS) vnstat.c vnstat.h

-	$(CC) $(CFLAGS) -lm -o vnstat vnstat.c $(OBJS)

+	$(CC) $(CFLAGS) -o vnstat vnstat.c $(OBJS) -lm

 ifinfo.o: ifinfo.c ifinfo.h vnstat.h db.h misc.h cfg.h

 	$(CC) $(CFLAGS) -c ifinfo.c