Rename basic_logging.c to basic.c, replacing the old version.

Having debugging on by default in the example seems to help
people trying out the library, and with the default_logger()
call it's not too much extra complication.

We should also write an example/complex.c that exercises
all the callback options, a custom allocator and so on.

examples/basic.c

@@ -0,0 +1,89 @@
+/* basic.c
+** libstrophe XMPP client library -- basic usage example
+**
+** Copyright (C) 2005 OGG, LCC. All rights reserved.
+**
+**  This software is provided AS-IS with no warranty, either express
+**  or implied.
+**
+**  This software is distributed under license and may not be copied,
+**  modified or distributed except as expressly authorized under the
+**  terms of the license contained in the file LICENSE.txt in this
+**  distribution.
+*/
+
+#include <stdio.h>
+
+#include <strophe.h>
+
+
+/* define a handler for connection events */
+void conn_handler(xmpp_conn_t * const conn, const xmpp_conn_event_t status, 
+		  const int error, xmpp_stream_error_t * const stream_error,
+		  void * const userdata)
+{
+    xmpp_ctx_t *ctx = (xmpp_ctx_t *)userdata;
+
+    if (status == XMPP_CONN_CONNECT) {
+	fprintf(stderr, "DEBUG: connected\n");
+	xmpp_disconnect(conn);
+    }
+    else {
+	fprintf(stderr, "DEBUG: disconnected\n");
+	xmpp_stop(ctx);
+    }
+}
+
+int main(int argc, char **argv)
+{
+    xmpp_ctx_t *ctx;
+    xmpp_conn_t *conn;
+    xmpp_log_t *log;
+    char *jid, *pass;
+    char *server;
+
+    /* take a jid and password on the command line,
+       with optional server to connect to */
+    if ((argc < 3) || (argc > 4)) {
+	fprintf(stderr, "Usage: basic <jid> <pass> [<server>]\n\n");
+	return 1;
+    }
+    
+    jid = argv[1];
+    pass = argv[2];
+    server = NULL;
+    /* Normally we pass NULL for the connection domain, in which case
+       the library derives the target host from the jid, but we can
+       override this for testing. */
+    if (argc >= 4) server = argv[3];
+    
+    /* init library */
+    xmpp_initialize();
+
+    /* create a context */
+    log = xmpp_get_default_logger(XMPP_LEVEL_DEBUG); /* pass NULL instead to silence output */
+    ctx = xmpp_ctx_new(NULL, log);
+
+    /* create a connection */
+    conn = xmpp_conn_new(ctx);
+
+    /* setup authentication information */
+    xmpp_conn_set_jid(conn, jid);
+    xmpp_conn_set_pass(conn, pass);
+
+    /* initiate connection */
+    xmpp_connect_client(conn, server, conn_handler, ctx);
+
+    /* enter the event loop - 
+       our connect handler will trigger an exit */
+    xmpp_run(ctx);
+
+    /* release our connection and context */
+    xmpp_conn_release(conn);
+    xmpp_ctx_free(ctx);
+
+    /* final shutdown of the library */
+    xmpp_shutdown();
+
+    return 0;
+}