Odoo Release Updates

[FIX] mass_mailing: fix wrong template strange xpath without inherit

[FIX] html_builder, mass_mailing: add custom snippets' group security

[FIX] *: allow mailing user to create favorite snippets

[IMP] html_builder, mass_mailing, website: add mass_mailing favorite snippets

[REF] html_builder, *: make options declaration and order XML-based

[REF] *: reduce datas usage

[IMP] *: remove unnecessary button "Discard" labels

[IMP] *: rename "Cancel" to "Discard"

[IMP] mass_mailing{_crm}: add tip on missing leads

[IMP] web: edit_tags_list

[IMP] mass_mailing: favorite template previews

[REF] web_studio, html_editor: Make dynamic field plugin generic

[IMP] mass_mailing, *: tweak recipient selection

[REF] html_editor, *: rename handlers and their editor functions

[IMP] mass_mailing: enlarge mailing editor

[FIX] html_editor, mass_mailing: apply data-selection-placeholder style

[IMP] mass_mailing: up text template font size

[IMP] mass_mailing: mailing view tweaks

[FIX] mass_mailing: fix infinite scrolling and ghost paragraphs

[FIX] mass_mailing: align the option's button when empty

[FIX] mass_mailing: fix history operations for conditionally visible snippets

[IMP] web,*: kanban,list: use <button> tags to add records

[FIX] html_editor, mass_mailing: deepest position inside non-editable

[IMP] html_builder, *: rename resource and class

[IMP] mass_mailing: add favorite snippets

[IMP] mass_mailing(_themes): increment mass_mailing snippets vxml

[IMP] html_builder, *: rename the o_editable class by o_savable

[FIX] mass_mailing: fix HtmlField usages in Form view

[IMP] mass_mailing(_sms): open campaign mailing in full form view

[FIX] mass_mailing: notify user of obsolete snippets