mimemail 8.x-1.0-alpha3

This is the first release that supports Drupal core 9.0. (Although D9.0 has been supported in 8.x-1.x-dev for two months already).

This is the last release that supports Drupal core 8.7.

Changes since 8.x-1.0-alpha2:

Bug fixes:

• #3145542 by TR, rivimey: MimeMailFormatHelper::mimeMailRfcHeaders() doesn't follow the RFC specification
• #3145007 by TR: Simplify option in MimeMailFormatHelper::mimeMailAddress() does not work when using string email addresses
• #3145000 by TR: MimeMailFormatHelper::mimeMailAddress() doesn't handle User objects properly
• #3144991 by TR: MimeMailFormatHelper::mimeMailUrl() doesn't use boolean type properly
• #3135735 by TR: Make mimemail-message.html.twig produce valid HTML
• #2801187 by danylevskyi, jerdavis, Klemen Pevec, audriusb, rick.kowal: Mailsystem crashes when the code is invoked via Drush
• #2938963 by hansfn, TR, colan: Sender Mime Mail mailer fails without explanation
• #2885904 by pcambra, colan, TR: Default filter format is non-existent

New features:

• #3146502 by TR: Make 'Send plain text email only' setting actually work
• #3145039 by TR: Make 'Use simple address format' setting actually work
• #3135736 by TR: Add base theme hook extension to mimemail_example
• #3132999 by TR: Template file naming and suggestions
• #3129729 by TR: Change path to mimemail_example form
• #3128810 by TR: Add new permission for sending test email with mimemail_example
• #2987698 by TR: Port mimemail_example module to D8.
• #2986723 by TR: Many settings not ported to D8 yet
• #2983816 by TR, Xano: Add basic config schemas / fix AdminForm

Testing:

Code cleanup:

• #3146519 by TR: Use ::class constant instead of namespaced strings
• #3145040 by TR: Rename MimeMailKernelTest to MimeMailFormatHelperTest
• #3136090 by TR: Use dependency injection in MimeMail Mail plugin
• #3111496 by imclean, TR: Remove Mime Mail engine code
• #3133006 by TR: Use Mail::formatDisplayName() instead of Unicode::mimeHeaderEncode()
• #3133004 by TR: Document and simplify Twig template
• #3129831 by TR: Add descriptions to all ExampleForm fields
• #3129816 by TR: ExampleForm attachments should be uploaded to temporary://
• #3127906 by TR, anrikun: Spelling and punctuation
• #3126782 by TR: Conditionally replace FileSystem::uriScheme() until Drupal 8.8 becomes the lowest-supported core version
• #3126782 by TR: Conditionally replace file_uri_scheme() until Drupal 8.8 becomes the lowest-supported core version
• #3126887 by TR: Deprecation: add $defaultTheme to browser tests
• #3053311 by TR: Function visibility - D8
• #3051208-18 by TR: Coding standards
• #2999009 by chipway: Update Format of Dependencies in .info.yml
• #2986145 by TR: Use mb_* functions instead of Unicode::* methods
• #2986160 by TR: drupal_get_message() and drupal_set_message() replaced by Messenger service
• #2986156 by TR: getFormID() should be getFormId()