Require GNU make to build sbase

We seem to have problems building individual tools across various
make implementations.  If anyone can step up and fix this we will
remove the dependency on GNU make.

Makefile

@@ -126,12 +126,9 @@ OBJ = $(BIN:=.o) $(LIBOBJ)
 SRC = $(BIN:=.c)
 MAN = $(BIN:=.1)
 
-all: binlib
+all: $(BIN)
 
-binlib: $(LIB)
-	$(MAKE) bin
-
-bin: $(BIN)
+$(BIN): $(LIB)
 
 $(OBJ): $(HDR) config.mk
 

README

@@ -170,6 +170,8 @@ form a base system similar to busybox but much smaller and suckless.
 Building
 --------
 
+You need GNU make to build sbase.
+
 To  build sbase,  simply  type  make.  You  may  have  to fiddle  with
 config.mk depending on your system.
 

config.mk

@@ -5,8 +5,9 @@ VERSION = 0.0
 PREFIX = /usr/local
 MANPREFIX = $(PREFIX)/share/man
 
-#CC = musl-gcc
+CC = cc
 LD = $(CC)
+AR = ar
 RANLIB = ranlib
 
 CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_GNU_SOURCE