Add first, experimental version of 'sleep on empty flag'.
Test
run_tests
[ 88%] Building CXX object test/CMakeFiles/tests.dir/main.cpp.o
[ 90%] Building CXX object test/CMakeFiles/tests.dir/data_structures_test.cpp.o
[ 92%] Building CXX object test/CMakeFiles/tests.dir/base_tests.cpp.o
[ 94%] Building CXX object test/CMakeFiles/tests.dir/scheduling_tests.cpp.o
[ 96%] Building CXX object test/CMakeFiles/tests.dir/patterns_test.cpp.o
[ 98%] Building CXX object test/CMakeFiles/tests.dir/scheduling_lock_free_tests.cpp.o
[100%] Linking CXX executable ../bin/tests
[100%] Built target tests
ERROR: Job failed: execution took longer than 1h0m0s seconds