Undocumented blocksci_parser flags

[geofurb]

The blocksci_parser tool has several flags in its help menu which are missing from the documentation and aren't explained very clearly in the help menu.

Update operations:
update
Update all BlockSci data

core-update
Update just the core BlockSci data (excluding indexes)
Should index operations only be used if core-update is called? What's the benefit/drawback to doing so?

--max-block, -m <max block>
Max block height to scan up to
Can negative arguments be passed in (e.g. -m -10000 to parse all but the last 10,000 blocks)?

Index operations:
index-update
Update indexes to latest chain state

address-index-update
Update address index to latest state

hash-index-update
Update hash index to latest state

compact-indexes
Compact indexes to speed up blockchain construction
Does compacting indexes negatively affect performance in some other operation?

When should and shouldn't these be run? Can you provide more detail on what they do? Which operations risk corrupting data if they are interrupted?