Adopt Makefile for Windows. Update examples readme section

examples/http-server/Makefile

@@ -1,21 +1,28 @@
-PROG ?= example
-ROOT ?= $(realpath $(CURDIR)/../..)
-DEFS ?= -DMG_ENABLE_LINES=1 -DMG_ENABLE_IPV6=1 -DMG_ENABLE_SSI=1 -DMG_HTTP_DIRLIST_TIME=1
-CFLAGS ?= -I../.. -W -Wall $(DEFS) $(EXTRA)
-VCFLAGS = /nologo /W3 /O2 /I../.. $(DEFS) $(EXTRA) /link /incremental:no /machine:IX86
-VC98 = docker run -it --rm -e Tmp=. -v $(ROOT):$(ROOT) -w $(CURDIR) mdashnet/vc98
+SOURCES = main.c ../../mongoose.c  # Source code files
+CFLAGS = -W -Wall -Wextra -g       # Build options
+
+# Mongoose build options. See https://mongoose.ws/documentation/#build-options
+CFLAGS += -I ../..
+CFLAGS += -DMG_HTTP_DIRLIST_TIME=1 -DMG_ENABLE_SSI=1
+CFLAGS += -DMG_ENABLE_LINES=1 -DMG_ENABLE_IPV6=1
+
+ifeq ($(OS),Windows_NT)
+  # Windows settings. Assume MinGW compiler
+  PROG ?= example.exe           # Use .exe suffix for the binary
+  CC = gcc                      # Use MinGW gcc compiler
+  CFLAGS += -lws2_32            # Link against Winsock library
+  DELETE = cmd /C del /Q /F /S  # Command prompt command to delete files
+else
+  # Mac, Linux
+  PROG ?= example
+  DELETE = rm -rf
+endif
 
 all: $(PROG)
 	$(RUN) ./$(PROG) $(ARGS)
 
-$(PROG): main.c Makefile
-	$(CC) ../../mongoose.c main.c -I../.. $(CFLAGS) -o $@
-
-mongoose.exe: main.c
-	$(VC98) wine cl ../../mongoose.c main.c $(VCFLAGS) ws2_32.lib /out:$@
-
-mingw:
-	gcc ../../mongoose.c main.c -I../.. -W -Wall $(DEFS) -D_POSIX_C_SOURCE=200000L -lws2_32 -o mongoose.exe
+$(PROG): $(SOURCES)
+	$(CC) $(SOURCES) $(CFLAGS) $(CFLAGS_EXTRA) -o $@
 
 clean:
-	rm -rf $(PROG) *.o *.dSYM *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb mongoose mongoose_* mongoose.*
+	$(DELETE) $(PROG) *.o *.dSYM