Fix method call to purgeObject to remove NPE
Add commons-io to client library for swing client
Conditional-Get should work for HEAD and GET

send conditional get headers to external DS sources in HEAD request pass-through

DefaultExternalContentManager to send 304s for controlGroup E file URIs when appropriate

check HEAD remote responses for 304 and pass back as appropriate
Handle open-ended byte range requests

Return RangeNotSatisfiableException for invalid ranges
on external local file datastreams

Enable pass-through Range requests and responses for external URL datastreams
TestAPIM should clean up test resources between tests
Debug tests execution as first step in fixing release IT workflow
explicitly set repository name and owner for site plugin
[maven-release-plugin] prepare release v3.8.0
Merge tag 'v3.8.0' into mssql

[maven-release-plugin]  copy for tag v3.8.0