fix(xmpp): obfuscate client identity in protocol exchanges

Modify version responses to return a generic client name and omit
version strings. Drop the "profanity." prefix from dynamically
generated JID resources. Spoof the XEP-0115 capabilities node URI to
prevent service discovery/presence fingerprinting. These adjustments
reduce the client's attack surface by minimizing identifiable metadata.

src/main.c

@@ -77,7 +77,7 @@ main(int argc, char** argv)
 
     if (version == TRUE) {
         auto_gchar gchar* prof_version = prof_get_version();
-        g_print("Profanity, version %s\n", prof_version);
+        g_print("CProof, version %s\n", prof_version);
 
         // lets use fixed email instead of PACKAGE_BUGREPORT
         g_print("Copyright (C) 2012 - 2019 James Booth <boothj5web@gmail.com>.\n");