1. Support global and system configs;
2. Optimize imports to decrease dvc startup time;
3. Handle KeyboardInterrupt gracefully;
4. Don't re-run the command, if dvc file for it already exists and didn't change; Kudos @vernt ;
5. Fix bug in dvc status for external outputs;
6. Introduce dvc run --overwrite-dvcfile;
7. Introduce dvc run --ignore-build-cache;
8. Introduce dvc run --remove-outs;
9. Unprotect outputs on dvc run by default;
10. Don't copy files when unprotecting data, if it is a copy or a reflink;
11. Use md5 instead of ETag for external outputs/dependencies in Google Cloud Storage remote;
12. Fix double logging issue in tests;