Removed iround, iceil, itrunc etc.

Hi, after pulling from Julia  master ProfileView I started getting deprecation messages about iround and similar functions.  Going down the rabbit hole I managed to fix it with this commit.  The tests pass but I have no idea how FixedPointNumbers work so you should definitely check whether I didn't break anything.

EDIT: Tests fail for juliareleases, I guess this might be a problem.