Added common files.

.gitlab-ci.yml

include/benchmark.h

include/clipp.h

include/exception.h

include/mt.h

include/plot.h

include/util.h

options/env.sh

tools/dev-shell

tools/download.sh

util/build_detector.sh

util/collect_benchmarks.py

util/collect_tests.py

util/compile_analyses.py

util/parse_cmd.sh

util/print_env.sh

util/run_many.py