Cyclic renaming

[neurobin]

rnm should (and will in some future release) support cyclic renaming.

A rudimentary algorithm:

1. Detect if cyclic renaming is applicable when a rename fails (if target exists in the queue).
2. If cyclic rename is possible, save the file and the target name to different queue vectors skipping it in the main queue, otherwise skip normally (with warning).
3. Process the cyclic queue vectors separately after the main queue finishes (thus the cyclic vectors will be complete) and log every rename steps in undo files sequentially (otherwise undo won't work).