Revert "sd-bus: check return value of asprintf()"

This reverts commit b1543c4c93855b61b40118e9f14a0423dac2e078.

We check b->address anyway, no need to check the return value,
especially given that the other #ifdef branch don't get the same
treatment.
sd-bus: explicitly cast asprintf() return value away we are not interested in

Let's give coverity a hint what's going on here.
update NEWS
update TODO
calendar: new case 'minutely'
man: document what "minutely" now means