-  gitty_history(+Store, +NameOrHash, -History, +Options) is det
 - History is a dict holding a key 
history with a list of dicts
representating the history of Name in Store. The toplevel dict
also contains skipped, indicating the number of skipped items
from the HEAD. Options:
- depth(+Depth)
 - Number of entries in the history. If not present, defaults
to 5.
 
- includes(+HASH)
 - Ensure Hash is included in the history. This means that the
history includes the entry with HASH an (depth+1)//2 entries
after the requested HASH.