hostname redirection in the client should be off by default

[d-w-moore]

Applications should be able to freely open a data object without the client redirection coming in the way. This has turned out to be a problem because

• the redirection feature isn't well documented (#626 )
• when the feature is on, server hostnames are passed to the client for connection purposes which may not be reachable by the client.

Suggestions:

• the feature should be disabled by default for principle of least surprise-
• data_object.open()'s allow_redirect option can be used to override that default
• optionally, a setting could be added , i.e. irods.client_configuration.data_objects.allow_redirect as a global flag that tells PRC to default to allow_redirect = True by default. A similar setting already exists for the auto-closing of data objects.

[alanking]

Just noting for posterity: While this is marked as a duplicate of #617, it has its own fix in #629 so we should not close it until that work has been merged.

[trel]

yes, sorry - agreed. still awaiting the fix to be merged.

[alanking]

@d-w-moore - Please close if complete. Thanks