The render_common_form_elements function was removed in the base class and it's contents put into the render_form_element function. These changes mean that some elements may not be required to override the render_form_element function, such as the studentname element, where this function was removed.
Elements are sub-plugins that have the same abilities as a core plugin, such as creating tables, capabilities and performing upgrades.
Currently elements can define -
* What additional form elements are rendered when adding the element to the customcert customisation page.
* How the data from the additional form elements is validated and saved.
* How the element is rendered on the PDF.
* How the element handles removing data when it is deleted.
