Use application context in SmackAndroid

Prevents "IllegalArgumentException: Receiver not registered:
org.jivesoftware.smack.SmackAndroid$ConnectivtyChangedReceiver"

Fixes #100.

static-src/custom/org/jivesoftware/smack/SmackAndroid.java

@@ -31,7 +31,8 @@ public void onReceive(Context context, Intent intent) {
 	private Context mCtx;
 
 	private SmackAndroid(Context ctx) {
-		mCtx = ctx;
+		// Use the application context to prevent "receiver not registered" messages
+		mCtx = ctx.getApplicationContext();
 		DNSUtil.setDNSResolver(DNSJavaResolver.getInstance());
 	}