dojox.rpc.JsonRPC Doesn't Deserialize Errors Correctly

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This ticket has to do with the switch to dojo/request in 1.8.

In JsonRPC's deserialize function, there is a check to see if the obj passed in has the name 'Error' and if it does, it parses the response text. If the response text has an error property e.g. { "error": "This is an error" }, deserialize would throw a new Error object with the error property's value as the message.

In 1.7, this worked because an Error object (name="Error") would be passed into deserialize.

In 1.8, it doesn't work because a RequestError? object is passed in (name="RequestError?"). A generic "Unable to load ..." message is always returned.

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In [30636]:

Workaround 1.7->1.8 API regression where the format of XHR errors changed unexpectedly. Fixes #16256.

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In [30637]:

Backport xhr regression fix to 1.8. Refs #16256.

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In [31078]:

Complete curious half-checkin. Refs #16256. Fixes #16947.

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In [31079]:

Complete curious half-checkin. Refs #16256. Fixes #16947.