allow building just the library not the testapps

From an idea by Jack Mitchell <ml@communistcode.co.uk>

Use --without-testapps at configure time to suppress building them

Signed-off-by: Andy Green <andy.green@linaro.org>

Makefile.am

@@ -1,5 +1,9 @@
 
+if NO_TESTAPPS
+SUBDIRS=lib
+else 
 SUBDIRS=lib test-server
+endif
 
 EXTRA_DIST=scripts/kernel-doc
 

README-test-server

@@ -73,6 +73,8 @@ There are several other possible configure options
 			implementation into the library.  By default your libc
 			one is used.
 
+--without-testapps	Just build the library not the test apps
+
 
 Externally configurable important constants
 -------------------------------------------

configure.ac

@@ -72,7 +72,17 @@ CFLAGS="$CFLAGS -DLWS_EXT_GOOGLE_MUX"
 fi
 AM_CONDITIONAL(EXT_GOOGLE_MUX, test x$x_google_mux = xyes)
 
-#                                                                               
+# 
+#
+#
+AC_ARG_WITH(testapps,
+ [  --without-testapps  dont build the libwebsocket-test- apps],
+ [ no_testapps=yes
+ ])
+
+AM_CONDITIONAL(NO_TESTAPPS, test x$no_testapps = xyes)
+
+
 #                                                                               
 #                                                                               
 AC_ARG_ENABLE(mingw,