Column indexes: Truncate min/max values

[asfimport]

Reporter: Gabor Szadovszky / @gszadovszky
Assignee: Gabor Szadovszky / @gszadovszky

Related issues:

• Column indexes: read/write API (depends upon)

PRs and other links:

• GitHub Pull Request #481

_{Note: This issue was originally created as PARQUET-1214. Please see the migration documentation for further details.}