Log Message:
tex-oberdiek{,-doc}: update to 2018.49285

Fixing several issues reported at
https://github.com/ho-tex/oberdiek/issues
Also the code has been simplified removing code paths for obsolete
versions of luatex and removing dependcies on the luatex85
compatibility package. the build system has been improved, with all the
existing test files converted to l3build and reference results checked.