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 e-mail templates and partials.

Affected Installations

All installations that use their own templates and partials for the e-mails. All installations that use an own layout file for the e-mails.

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.