Merge branch 'release/v2.8.1' into develop
updating to version 2.8.1
Fixing a bug that could cause phantom emails.
Fixed a bug that could prevent emails from being sent if the message was empty.
Fixed a bug with email notifications that could prevent an empty message from being sent.
Added a filter for success message notifications: nf_success_msg.
Added a filter for CSV exports after labels have been added but before fields: nf_subs_csv_label_array_before_fields.
Deprecated the old version of the success message filter.
Fixed a bug with upgrades that caused submission conversion to fail.
Fixed PHP notices.
Updating to version 2.8.2.
Merge branch 'release/v2.8.2'