Created Newsletter

Signed-off-by: René Meye <rene@meye.md>
Added ability to delay sending newsletter in background

Signed-off-by: René Meye <rene@meye.md>
Moving Groups under Courses

Signed-off-by: René Meye <rene@meye.md>
Simplified active_admin js include

Signed-off-by: René Meye <rene@meye.md>
Recycled Mails from old Posts system

Signed-off-by: René Meye <rene@meye.md>
Fixed subject from confirmation Mail

Signed-off-by: René Meye <rene@meye.md>
Fixed Faculty.users having duplicate entries

Signed-off-by: René Meye <rene@meye.md>
Build stable background Newsletter system

* don't send E-Mails twice in case of a fail
* shows done process
* can send to degree_programs or all user or without_degree_programs

Signed-off-by: René Meye <rene@meye.md>
Made a clearer Preregisterd Login/Extend account workflow

Signed-off-by: René Meye <rene@meye.md>
Included Tags for Newsletter

Signed-off-by: René Meye <rene@meye.md>
Fixed some Bugs with sql-querys

Signed-off-by: René Meye <rene@meye.md>
Hint for placeholders

Signed-off-by: René Meye <rene@meye.md>