improve frontend of emacs, ckeditor, tinymce, nicedit, meta and env functions

Improves in emacs:
- use htmx to send content to the controller
- show txt and formatted_txt content in the second panel
- show two tabs if "tabs" winix parameter is used
- add an option to show either one or two panels
- correctly resize the editor window (F11) when two panels are shown

Improves in ckeditor:
- use htmx to send content to the controller
- do not check automatically for ckeditor update

Improves in tinymce/nicedit/meta/env:
- use htmx to send content to the controller

while here:
- change PascalCase to snake_case in meta/env controllers
- update CodeMirror editor to 5.65.16
- udpate Showdown (markdown to html converter) to 2.1.0

winixd/functions/meta.h

@@ -38,11 +38,8 @@
 #include "functionbase.h"
 #include "space/spaceparser.h"
 
-namespace Winix
-{
 
-
-namespace Fun
+namespace Winix::Fun
 {
 
 
@@ -52,26 +49,25 @@ public:
 
 	Meta();
 
-	bool has_access();
-	void make_post();
+	bool has_access() override;
+	void make_post() override;
 
-	bool EditAdminMeta(Item & item, const std::wstring & meta_str);
-	bool EditMeta(Item & item, const std::wstring & meta_str);
 
 private:
 
 	pt::SpaceParser conf_parser;
 	pt::Space space;
 
-	bool Parse(const std::wstring & meta_str);
-	void ChangeAdminMeta();
-	void ChangeMeta();
+	bool edit_admin_meta(Item & item, const std::wstring & meta_str);
+	bool edit_meta(Item & item, const std::wstring & meta_str);
+
+	bool parse(const std::wstring & meta_str);
+	void change_admin_meta();
+	void change_meta();
 
 };
 
 
 } // namespace
 
-} // namespace Winix
-
 #endif