* Introduce the isodate(), isotime(), and isodatetime() template filters
* Display the relative time on mouse hover
* Render journal entry times in ISO 8601 format
* Use ISO 8601 format when displaying dates & times in a table
* Standardize the use of DateTimeColumn across all tables
* Introduce custom form widget templates to apply CSS classes
* Apply both mandatory and optional CSS classes to form widgets
* Omit required & placeholder attrs
* Move annotation of field validation failures to CSS
* Remove BootstrapMixin class
* Remove obsolete ComponentTemplateImportForm class
* Remove obsolete custom forms for login & password change
* Clean up obsolete accommodations for 'required' widget attr
