Breaking: #288 - Change MailHandler to FluidEmail

See Issue #288

Description

The changeover from rendering an own standalone view to the FluidEmail class required adjustments in the email templates and partials.

Affected Installations

All installations that use their own templates and partials for the emails. All installations that use an own layout file for the emails.

Migration

To be able to use your own templates and parts, the folders where the files are located must be included via $GLOBALS['TYPO3_CONF_VARS']['MAIL']. The extension has included the following in the ext_localconf.php

$GLOBALS['TYPO3_CONF_VARS']['MAIL']['templateRootPaths']['1588829280'] = 'EXT:cart/Resources/Private/Templates/';
$GLOBALS['TYPO3_CONF_VARS']['MAIL']['partialRootPaths']['1588829280'] = 'EXT:cart/Resources/Private/Partials/';

To ensure the correct order, the own key (UNIX timestamp) must be larger.

Furthermore you should compare your own templates and partials with those of the extension.