Bidirectional text improvements (#4541)

* Add support for \dir pragma

* Add "dir" attribute to reveal, edit, edit-text and edit-codemirror widgets

* Add  $:/config/DefaultTextDirection hidden setting

* Revert accidentally commited test data

This reverts some of commit b83c1d160f.

* Remove Codemirror plugin from Prerelease

Makes it easier to test things

* Fix framed text editor directionality in Firefox

* Add direction attribute for edit body template

* Missed closing brace

* Add docs for \dir pragma

* Templates should set text direction from a variable, not a transclusion

* Updates to framed.js in the light of PRs that have been merged since this

* Restore whitespace trim

* Docs dates

* Fix typo

* Clarify docs

core/ui/EditTemplate/body/default.tid

@@ -15,7 +15,7 @@ $:/config/EditorToolbarButtons/Visibility/$(currentTiddler)$
 	importState=<<qualify $:/state/ImportImage>> >
 <$dropzone importTitle=<<importTitle>> autoOpenOnImport="no" contentTypesFilter={{$:/config/Editor/ImportContentTypesFilter}} class="tc-dropzone-editor" enable={{{ [{$:/config/DragAndDrop/Enable}match[no]] :else[subfilter{$:/config/Editor/EnableImportFilter}then[yes]else[no]] }}} filesOnly="yes" actions=<<importFileActions>> >
 <$reveal stateTitle=<<edit-preview-state>> type="match" text="yes" tag="div">
-<div class="tc-tiddler-preview">
+<div class="tc-tiddler-preview" dir=<<tv-text-direction>>>
 
 <$transclude tiddler="$:/core/ui/EditTemplate/body/editor" mode="inline"/>
 
@@ -32,7 +32,7 @@ $:/config/EditorToolbarButtons/Visibility/$(currentTiddler)$
 </div>
 </$reveal>
 
-<$reveal stateTitle=<<edit-preview-state>> type="nomatch" text="yes" tag="div">
+<$reveal stateTitle=<<edit-preview-state>> type="nomatch" text="yes" tag="div" dir=<<tv-text-direction>>>
 
 <$transclude tiddler="$:/core/ui/EditTemplate/body/editor" mode="inline"/>