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/html/ckeditor.html

@@ -88,7 +88,8 @@ coreStyles_underline :
 
     //config.allowedContent : true, // allowes all
 disallowedContent : 'p(western)', // from copying from Office
-extraAllowedContent : 'aside caption figure figcaption article footer header section div (*); ul(*); ol(*); h1(*); h2(*); h3(*); h4(*); h5(*); h6(*); p(*); table(*); tr(*); td(*);'
+extraAllowedContent : 'aside caption figure figcaption article footer header section div (*); ul(*); ol(*); h1(*); h2(*); h3(*); h4(*); h5(*); h6(*); p(*); table(*); tr(*); td(*);',
+versionCheck: false
 
 });
 
@@ -167,7 +168,8 @@ coreStyles_underline :
 
     //config.allowedContent : true, // allowes all
 disallowedContent : 'p(western)', // from copying from Office
-extraAllowedContent : 'aside caption figure figcaption article footer header section (*); ul(*); h1(*); h2(*); p(*)'
+extraAllowedContent : 'aside caption figure figcaption article footer header section (*); ul(*); h1(*); h2(*); p(*)',
+versionCheck: false
 
 });