More Variable Convert functions

We have in Variable Convert the following:

- Date Time to Seconds: date can be in YYYYMMDD format or xx-yy-zz, in which case the positions of day, month and year are determined by Android preferences. So to code locale-independent you always have to use the first format YYYYMMDD hh.mm

- Seconds to Date Time: returns the localized format

But we don't have a native Tasker function to get from seconds the first format. So we would need a 'Seconds to Date Time (YYYYMMDD hh.mm)'

Furthermore a 'Seconds to day nr of week' would be useful.