February 2018 release

New Levels:

1. DMLab-30.

   1. contributed/dmlab30/rooms_collect_good_objects_{test,train}
   2. contributed/dmlab30/rooms_exploit_deferred_effects_{test,train}
   3. contributed/dmlab30/rooms_select_nonmatching_object
   4. contributed/dmlab30/rooms_watermaze
   5. contributed/dmlab30/rooms_keys_doors_puzzle
   6. contributed/dmlab30/language_select_described_object
   7. contributed/dmlab30/language_select_located_object
   8. contributed/dmlab30/language_execute_random_task
   9. contributed/dmlab30/language_answer_quantitative_question
   10. contributed/dmlab30/lasertag_one_opponent_small
   11. contributed/dmlab30/lasertag_three_opponents_small
   12. contributed/dmlab30/lasertag_one_opponent_large
   13. contributed/dmlab30/lasertag_three_opponents_large
   14. contributed/dmlab30/natlab_fixed_large_map
   15. contributed/dmlab30/natlab_varying_map_regrowth
   16. contributed/dmlab30/natlab_varying_map_randomized
   17. contributed/dmlab30/skymaze_irreversible_path_hard
   18. contributed/dmlab30/skymaze_irreversible_path_varied
   19. contributed/dmlab30/psychlab_sequential_comparison
   20. contributed/dmlab30/psychlab_visual_search
   21. contributed/dmlab30/explore_object_locations_small
   22. contributed/dmlab30/explore_object_locations_large
   23. contributed/dmlab30/explore_obstructed_goals_small
   24. contributed/dmlab30/explore_obstructed_goals_large
   25. contributed/dmlab30/explore_goal_locations_small
   26. contributed/dmlab30/explore_goal_locations_large
   27. contributed/dmlab30/explore_object_rewards_few
   28. contributed/dmlab30/explore_object_rewards_many

New Features:

1. Basic support for demo recording and playback.

Minor Improvements:

1. Add a mechanism to build DeepMind Lab as a PIP package.
2. Extend basic testing to all levels under game_scripts/levels.
3. Add settings minimalUI and reducedUI to avoid rendering parts of the HUD.
4. Add teleported flag to game:playerInfo() to tell whether a player has teleported that frame.
5. Add Lua functions countEntities and countVariations to the maze generation API to count the number of occurrences of a specific entity or variation, respectively

Bug Fixes:

1. Fix out-of-bounds access in Lua 'image' library.
2. Fix off-by-one error in renderergl1 grid mesh rendering.