Hide enchant dependency from public headers

There is no real need to expose the dependency and with the change
of the enachant version it could be problematic to forward the right
enchant include folder to the library user, thus it's easier to just
hide the dependency.

src/e-util/e-spell-checker.c

@@ -18,6 +18,8 @@
 
 #include "evolution-config.h"
 
+#include <enchant.h>
+
 #include "e-spell-checker.h"
 #include "e-spell-dictionary.h"
 
@@ -386,7 +388,7 @@ e_spell_checker_ref_dictionary (ESpellChecker *checker,
  *
  * Returns: the #EnchantDict for @language_code, or %NULL
  **/
-EnchantDict *
+gpointer
 e_spell_checker_get_enchant_dict (ESpellChecker *checker,
                                   const gchar *language_code)
 {

src/e-util/e-spell-checker.h

@@ -71,7 +71,8 @@ guint		e_spell_checker_count_available_dicts
 ESpellDictionary *
 		e_spell_checker_ref_dictionary	(ESpellChecker *checker,
 						 const gchar *language_code);
-EnchantDict *	e_spell_checker_get_enchant_dict
+gpointer /* EnchantDict * */
+		e_spell_checker_get_enchant_dict
 						(ESpellChecker *checker,
 						 const gchar *language_code);
 gboolean	e_spell_checker_get_language_active

src/e-util/e-spell-dictionary.c

@@ -18,6 +18,8 @@
 
 #include "evolution-config.h"
 
+#include <enchant.h>
+
 #include "e-util-private.h"
 #include "e-spell-dictionary.h"
 #include "e-spell-checker.h"
@@ -437,7 +439,7 @@ e_spell_dictionary_init (ESpellDictionary *dictionary)
 
 ESpellDictionary *
 e_spell_dictionary_new (ESpellChecker *spell_checker,
-                        EnchantDict *enchant_dict)
+                        gpointer enchant_dict)
 {
 	ESpellDictionary *dictionary;
 

src/e-util/e-spell-dictionary.h

@@ -24,7 +24,6 @@
 #define E_SPELL_DICTIONARY_H
 
 #include <glib-object.h>
-#include <enchant.h>
 
 /* Standard GObject macros */
 #define E_TYPE_SPELL_DICTIONARY \
@@ -66,7 +65,7 @@ struct _ESpellDictionaryClass {
 GType		e_spell_dictionary_get_type	(void) G_GNUC_CONST;
 ESpellDictionary *
 		e_spell_dictionary_new		(struct _ESpellChecker *spell_checker,
-						 EnchantDict *enchant_dict);
+						 gpointer enchant_dict); /* EnchantDict * */
 ESpellDictionary *
 		e_spell_dictionary_new_bare	(struct _ESpellChecker *spell_checker,
 						 const gchar *language_tag);