+ add checks for search directive in normalization to parser
+ lookup to another input file
+ support splitting of config yml to multiple files
++ add set and get to create in-memory lookup
++ support marc_remove('*')
+- load_ds/save_ds should use on-disk hash to preserve inodes
+- leader(position,...), indicator(field,nr) nr=1|2 for MARC input
- fix-length fields (<100) support
- validate should ignore modify_file
- add option to specify output marc path in config.yml