Support whitespace between language codes

So far, when configuring multiple spell check languages, Hexchat
requires the user to separate multiple entries with commas and
only commas. This patch allows users to also enter whitespace, e.g.

  de_DE, en_US

as is common in many applications.

src/fe-gtk/sexy-spell-entry.c

@@ -1255,7 +1255,7 @@ void
 sexy_spell_entry_activate_default_languages(SexySpellEntry *entry)
 {
 	GSList *enchant_langs;
-	char *lang, *langs;
+	char *lang, **i, **langs;
 
 	if (!have_enchant)
 		return;
@@ -1265,21 +1265,21 @@ sexy_spell_entry_activate_default_languages(SexySpellEntry *entry)
 
 	enchant_langs = sexy_spell_entry_get_languages(entry);
 
-	langs = g_strdup (prefs.hex_text_spell_langs);
+	langs = g_strsplit_set (prefs.hex_text_spell_langs, ", \t", 0);
 
-	lang = strtok (langs, ",");
-	while (lang != NULL)
+	for (i = langs; *i; i++)
 	{
+		lang = *i;
+
 		if (enchant_has_lang (lang, enchant_langs))
 		{
 			sexy_spell_entry_activate_language_internal (entry, lang, NULL);
 		}
-		lang = strtok (NULL, ",");
 	}
 
 	g_slist_foreach(enchant_langs, (GFunc) g_free, NULL);
 	g_slist_free(enchant_langs);
-	g_free (langs);
+	g_strfreev (langs);
 
 	/* If we don't have any languages activated, use "en" */
 	if (entry->priv->dict_list == NULL)