The moveInVector() function was defined in qthelper.h, even
though it has nothing to do with Qt. Therefore, move it into
its own header.
Morover, since it is a very low-level function, use snake_case.
And rename it to move_in_range(), because it does not only
work on vectors, but any range with random-access iterators.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
94641c510f