slow_impulses v1.0.1: bugfix duration

duration was too long if you want to reach a defined number of
intervals by passing duration and frequency only (not the number
directly)
IntervalTrigger v2.0.2: bug at long execution times

at long execution times there was an integer overflow in one
calculation. Fixed by explicit conversion to long
Merge pull request #1 from jtByt-Pictures/v2.1-dev

v2.0.2 bugfixes with integer overflows