July 2019 - Slider Bars, Email Improvements, including multiple reminders

This release includes:

1.  The introduction of Slider bars as a Question Type
   • Sliders can be used with text or numerical answers
   • The Question Type (in the Question Dialogue box) is set to Slider.
   • The answer type for each answer must be Single choice Item (the same as used for Inline and Matrix single choice)
   • All answer rules are followed, as far as scoring and feedback reporting, etc are concerned.
2. Emails have been upgraded
   • The Editor has been upgraded to be full HTML, so you can more easily insert bullet points, numbering, tables, links etc, together with other formatting options.
   • A dropdown list has been added to insert merge strings into the text of the template
   • You can now have merge strings in the subject line.
   • Selecting a Merge String from the selector will insert the correctly formatted merge string at the current cursor position in the template text.  
   • You can now copy emails (from the list screen)
   • For "Auto Reminder" emails the Days after Response Created has moved from the Assessment to the email template.  This means that you can have multiple reminders, say after 2 days, 5 days, 10 days, 14 days etc.
   • There is a new Email type "Auto Reminder - Cohort Initiation".  These are similar to the "Auto Reminder" emails but are triggered when a Cohort Initiation is created and no Recipient records are created. Again you can have multiple records.
   • There is a new Email type "Manual Reminder - Cohort Initiation". These are sent at the same time as "Manual Reminders" (for responses) are sent if a Cohort Initiation is Present and no Recipient records have been created.
   • As there is now a two-part process to email sending, they will first appear on the Emails Sent display as "Pending".  Once they are sent  (usually within a minute) they will have a status of "Sent".  If there is an error on the email account they will have a status of "Retry".  Emails will be automatically retried 10 times.  
3. Some small fixes and improvements including:
   • Copying questions, subsections, sections, and assessments sometimes didn't copy the question conditions on individual questions
   •  Rating table at Question Level now uses the full Question text.
   • A number of fixes with emails.