icofoam/cavity/cavity

supposedly (CdEDokuTeam) standard package that just improves things

This reverts commit ecdbc9cc.

This is not longer necessary since okular is working fine on new fedora
installation.

also explains one more option of .latexmkrc

better solution would be to avoid / in usepackage:
https://tex.stackexchange.com/questions/31925/install-package-in-subfolder/31950#31950
but I didn't find how to set the env variable TEXINPUTS in .latexmkrc