Small spelling fixes in code and comments

src/ui/inputwin.c

@@ -272,7 +272,7 @@ _clear_input(void)
 /*
  * Deal with command editing, return 1 if ch was an edit
  * key press: up, down, left, right or backspace
- * return 0 if it wasnt
+ * return 0 if it wasn't
  */
 static int
 _handle_edit(int result, const wint_t ch, char *input, int *size)

src/ui/notifier.c

@@ -121,7 +121,7 @@ _notify_subscription(const char * const from)
 {
     GString *message = g_string_new("Subscription request: \n");
     g_string_append(message, from);
-    _notify(message->str, 10000, "Incomming message");
+    _notify(message->str, 10000, "Incoming message");
     g_string_free(message, TRUE);
 }