Provide a gmake Makefile for distro builds and packagers.

Define _GNU_SOURCE in the CFLAGS.
Update the README.
Remove the duplicate Gentoo init script ndhc.sh that is in the root.
Remove DESIGN -- it's outdated.

Makefile

@@ -0,0 +1,42 @@
+# This is a pretty basic makefile.  I generally use CMake, so this is mostly
+# for distros that want to avoid build dependencies.  Produced exes will be
+# at './build/ndhc' and './build/ifchd'.
+
+NCM_SRCS = $(sort $(wildcard ncmlib/*.c))
+IFCHD_SRCS = $(sort $(wildcard ifchd/*.c))
+NDHC_SRCS = $(sort $(wildcard ndhc/*.c))
+NCM_OBJS = $(NCM_SRCS:.c=.o)
+IFCHD_OBJS = $(IFCHD_SRCS:.c=.o)
+NDHC_OBJS = $(NDHC_SRCS:.c=.o)
+NCM_INC = -I./ncmlib
+BUILD_DIR = build
+OBJ_DIR = objs
+
+CC = gcc
+AR = ar
+RANLIB = ranlib
+CFLAGS = -O2 -s -std=gnu99 -pedantic -Wall -D_GNU_SOURCE -DHAVE_CLEARENV -DLINUX
+
+all: makedir ncmlib.a ifchd ndhc
+
+clean:
+	rm -Rf $(OBJ_DIR) $(BUILD_DIR)
+
+makedir:
+	mkdir -p $(OBJ_DIR)/ndhc $(OBJ_DIR)/ifchd $(OBJ_DIR)/ncmlib $(BUILD_DIR)
+
+%.o: %.c
+	$(CC) $(CFLAGS) $(NCM_INC) -c -o $(OBJ_DIR)/$@ $<
+
+ncmlib.a: $(NCM_OBJS)
+	$(AR) rc $(BUILD_DIR)/$@ $(subst ncmlib/,$(OBJ_DIR)/ncmlib/,$(NCM_OBJS))
+	$(RANLIB) $(BUILD_DIR)/$@
+
+ifchd: $(IFCHD_OBJS)
+	$(CC) $(CFLAGS) $(NCM_INC) -o $(BUILD_DIR)/$@ $(subst ifchd/,$(OBJ_DIR)/ifchd/,$(IFCHD_OBJS)) $(BUILD_DIR)/ncmlib.a -lcap 
+
+ndhc: $(NDHC_OBJS)
+	$(CC) $(CFLAGS) $(NCM_INC) -o $(BUILD_DIR)/$@ $(subst ndhc/,$(OBJ_DIR)/ndhc/,$(NDHC_OBJS)) $(BUILD_DIR)/ncmlib.a -lcap
+
+.PHONY: all clean
+