Merge pull request #8623 from basilfx/feature/pkg_ucglib

pkg/ucglib/Makefile

pkg/ucglib/Makefile.include

pkg/ucglib/README.md

pkg/ucglib/doc.txt

pkg/ucglib/patches/0001-add-RIOT-OS-interface.patch

pkg/ucglib/src/Makefile

pkg/ucglib/src/csrc/Makefile

pkg/ucglib/src/csrc/ucg_riotos.c

pkg/ucglib/src/sys/sdl/dev/Makefile

tests/pkg_ucglib/Makefile

tests/pkg_ucglib/README.md

tests/pkg_ucglib/logo.h

tests/pkg_ucglib/main.c

tests/pkg_ucglib/tests/01-run.py