Issue #2361727 by rpayanm: Remove drupal_convert_to_utf8.
Issue #2361845 by rpayanm: Remove drupal_substr.
Issue #2371457 by DuaelFr: Replace inappropriate translatatable string in core/modules/contextual/contextual.module.
Issue #2367745 by Palashvijay4O | gumanist: Remove drupal_var_export().