wswrapper: wrap existing server using LD_PRELOAD.

wswrapper.so is LD_PRELOAD shared library that interposes and turns
a generic TCP socket into a WebSockets service.

This current version works but will only allow work for a single
connection, subsequent connections will not be wrapped. In addition
the wrapper interposes on the first incoming network connection. It
should read an environment variable to determine the port to interpose
on. Also, should limit origin based on another environment variable.
Then there should be a wswrap setup script that allows easier
invocation.

utils/Makefile

+TARGETS=wsproxy wswrapper.so 
+CFLAGS += -fPIC
+
+all: $(TARGETS)
+
 wsproxy: wsproxy.o websocket.o md5.o
-	$(CC) $(LDFLAGS) $^ -l ssl -lcrypto -l resolv -o $@
+	$(CC) $(LDFLAGS) $^ -lssl -lcrypto -lresolv -o $@
+
+wswrapper.so: wswrapper.o md5.o
+	$(CC) $(LDFLAGS) $^ -shared -fPIC -ldl -lresolv -o $@
 
 websocket.o: websocket.c websocket.h md5.h
 wsproxy.o: wsproxy.c websocket.h
+wswrapper.o: wswrapper.c
+	$(CC) -c $(CFLAGS) -o $@ $*.c
 md5.o: md5.c md5.h
-	$(CC) $(CFLAGS) -c -o $@ $*.c -DHAVE_MEMCPY -DSTDC_HEADERS
+	$(CC) -c $(CFLAGS) -o $@ $*.c -DHAVE_MEMCPY -DSTDC_HEADERS
 
 clean:
-	rm -f wsproxy wsproxy.o websocket.o md5.o
+	rm -f wsproxy wswrapper.so *.o