Merge branch 'release-v21.0' into develop
In OAI enrichment, check if record has a status of deleted
Bumped version number to 21.1
Merge branch 'release-v21.1'
Merge branch 'release-v21.1' into develop
Added catch for undefined sourceResource in enrich-type.

sourceResource can be missing in items where the status is "deleted".
Added threading to enrich_records (#7282)
Add catch for incomplete read in database export (#7155)

Added handling of IncompleteRead exception in
export_database.store_result_into_file().  This may not resolve
the issue of closed HTTP connections to CouchDB, but may give us
more information as to what sometimes fails.
Fixed Google thumbnail image URL in test for hathi_identify_object

This image URL has apparently changed.
Bumped version number to 22.0
Merge branch 'release-v22.0'
Merge branch 'release-v22.0' into develop
Restrict Digital Commonwealth fetch to sets not yet migrated to BPL
Merge branch 'restrict-dc-sets' into develop
Changes for new BPL, Digital Commonwealth sites; Geocoding fixes

- Resolve #7330: BPL spatial data, "United States" generic value
- Other geocoding improvements
- Fix #7488:  BPL dataProvider: add option to pull from
  recordInfo/recordContentSource
- Fix #7330 and #6097:  Created subject_and_spatial_transform_bpl to
  join spatial values on double-hyphen and add the coordinates
- Fix #7329: Iterify OAI-PMH/ListRecords/record, fix
  location_transform_bpl
Removed obsolete condition for Digital Commonwealth in test
Bumped version to 22.1
Merge branch 'release-v22.1'
Merge branch 'release-v22.1' into develop
Changed Akara MaxServers and MaxRequestsPerServer

MaxServers can be higher.  It's not an issue with memory consumption,
which is an issue with fetches, where a single process leaks memory.

MaxRequestsPerServer can also be higher.  500 is low enough that child
processes with memory leaks get killed soon enough, but higher than
the old value of 100.