Fix function prototypes for list of arguments

At the moment, building WeeChat triggers several thousand -Wstrict-prototypes
diagnostics.  This is due to its source code using an empty argument list for
functions and function pointers that take no arguments, instead of explicitly
declaring that they take no arguments by using a void list.

This commit replaces all empty argument lists with a void list.

Note that Ruby's headers also suffer the same problem, which WeeChat can't
do anything to fix.  Thus, building WeeChat with the Ruby plugin enabled
will still issue approximately 30 such diagnostics.

src/plugins/alias/alias-command.c

@@ -350,7 +350,7 @@ alias_command_cb (const void *pointer, void *data,
  */
 
 void
-alias_command_init ()
+alias_command_init (void)
 {
     struct t_hook *ptr_hook;
 

src/plugins/alias/alias-command.h

@@ -22,6 +22,6 @@
 
 #define ALIAS_COMMAND_KEEP_SPACES weechat_hook_set (ptr_hook, "keep_spaces_right", "1")
 
-extern void alias_command_init ();
+extern void alias_command_init (void);
 
 #endif /* WEECHAT_PLUGIN_ALIAS_COMMAND_H */

src/plugins/alias/alias-completion.c

@@ -115,7 +115,7 @@ alias_completion_alias_value_cb (const void *pointer, void *data,
  */
 
 void
-alias_completion_init ()
+alias_completion_init (void)
 {
     weechat_hook_completion ("alias", N_("list of aliases"),
                              &alias_completion_alias_cb, NULL, NULL);

src/plugins/alias/alias-completion.h

@@ -20,6 +20,6 @@
 #ifndef WEECHAT_PLUGIN_ALIAS_COMPLETION_H
 #define WEECHAT_PLUGIN_ALIAS_COMPLETION_H
 
-extern void alias_completion_init ();
+extern void alias_completion_init (void);
 
 #endif /* WEECHAT_PLUGIN_ALIAS_COMPLETION_H */

src/plugins/alias/alias-config.c

@@ -427,7 +427,7 @@ alias_config_update_cb (const void *pointer, void *data,
  */
 
 int
-alias_config_init ()
+alias_config_init (void)
 {
     alias_config_file = weechat_config_new (ALIAS_CONFIG_PRIO_NAME,
                                             &alias_config_reload, NULL, NULL);
@@ -470,7 +470,7 @@ alias_config_init ()
  */
 
 int
-alias_config_read ()
+alias_config_read (void)
 {
     return weechat_config_read (alias_config_file);
 }
@@ -480,7 +480,7 @@ alias_config_read ()
  */
 
 int
-alias_config_write ()
+alias_config_write (void)
 {
     return weechat_config_write (alias_config_file);
 }

src/plugins/alias/alias-config.h

@@ -35,8 +35,8 @@ extern void alias_config_cmd_new_option (const char *name,
                                          const char *command);
 extern void alias_config_completion_new_option (const char *name,
                                                 const char *completion);
-extern int alias_config_init ();
-extern int alias_config_read ();
-extern int alias_config_write ();
+extern int alias_config_init (void);
+extern int alias_config_read (void);
+extern int alias_config_write (void);
 
 #endif /* WEECHAT_PLUGIN_ALIAS_CONFIG_H */

src/plugins/alias/alias-info.c

@@ -139,7 +139,7 @@ alias_info_infolist_alias_default_cb (const void *pointer, void *data,
  */
 
 void
-alias_info_init ()
+alias_info_init (void)
 {
     weechat_hook_infolist (
         "alias", N_("list of aliases"),

src/plugins/alias/alias-info.h

@@ -20,6 +20,6 @@
 #ifndef WEECHAT_PLUGIN_ALIAS_INFO_H
 #define WEECHAT_PLUGIN_ALIAS_INFO_H
 
-extern void alias_info_init ();
+extern void alias_info_init (void);
 
 #endif /* WEECHAT_PLUGIN_ALIAS_INFO_H */

src/plugins/alias/alias.c

@@ -606,7 +606,7 @@ alias_free (struct t_alias *alias)
  */
 
 void
-alias_free_all ()
+alias_free_all (void)
 {
     while (alias_list)
     {

src/plugins/alias/alias.h

@@ -48,7 +48,7 @@ extern struct t_alias *alias_new (const char *name, const char *command,
                                   const char *completion);
 extern int alias_rename (struct t_alias *alias, const char *new_name);
 extern void alias_free (struct t_alias *alias);
-extern void alias_free_all ();
+extern void alias_free_all (void);
 extern int alias_add_to_infolist (struct t_infolist *infolist,
                                   struct t_alias *alias);