Android: always return an empty proxy

There are no simple ways to find the right proxy on Android, even in
Java. A proposed "solution" is suggested in the comments, but it would
require JNI. Feel free to implement :)

src/Makefile.am

@@ -258,6 +258,7 @@ SOURCES_libvlc_android = \
 	android/dirs.c \
 	android/thread.c \
 	posix/filesystem.c \
+	android/netconf.c \
 	posix/plugin.c \
 	posix/timer.c \
 	posix/linux_cpu.c \

src/android/netconf.c

+/*****************************************************************************
+ * netconf.c : Network configuration
+ *****************************************************************************
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
+#include <vlc_network.h>
+
+/* This is empty, of course
+ *
+ * The reason is that there is no simple way to get the proxy settings on all
+ * supported versions of Android, even from the Java side...
+ *
+ * The best way would be to follow this "solution"
+ * http://stackoverflow.com/questions/10811698/getting-wifi-proxy-settings-in-android/13616054#13616054
+ *
+ * Or, in summary, using JNI:
+ * if( version >= 4.0 ) {
+ *     System.getProperty( "http.proxyHost" );
+ *     System.getProperty( "http.proxyPort" );
+ * } else {
+ *     context = magically_find_context();
+ *     android.net.Proxy.getHost( context );
+ *     android.net.Proxy.getPort( context );
+ * }
+ *
+ * */
+
+/**
+ * Determines the network proxy server to use (if any).
+ * @param url absolute URL for which to get the proxy server
+ * @return proxy URL, NULL if no proxy or error
+ */
+char *vlc_getProxyUrl(const char *url)
+{
+    return NULL;
+}