Ported over the ``has_item`` call.
Fixes #1822
Fixed doc typos.
Merge branch 'ddb-has-item' into develop
Fixes #1973 & #1822
Add Glacier inventory retrieval date/limit support

Updates Glacier to the latest documentation strings and adds information
about the `InventoryRetrievalInput` fields to filter by date range and
to limit the number of inventory retrieval job results.
Updated the docs in support.
Merge branch 'support-docs-update' into develop
Import with_statement for old Python versions
Merge pull request #1975 from dpwatrous/develop

Import with_statement for old Python versions
Add Layer2 inventory date range / limit
Add Glacier layer2 test for date range / limit
Merge pull request #1977 from danielgtaylor/glacier-inventory

Add new Glacier inventory options. Fixes #1977.
Change GCS resumable upload handler to save tracker files with protection 0600