Bugfix: Fix a variety of misspellings

(PARTIAL: Left out anything changing debug.log)

src/irc.cpp

@@ -254,7 +254,7 @@ void ThreadIRCSeed(void* parg)
 
 void ThreadIRCSeed2(void* parg)
 {
-    /* Dont advertise on IRC if we don't allow incoming connections */
+    /* Don't advertise on IRC if we don't allow incoming connections */
     if (mapArgs.count("-connect") || fNoListen)
         return;