Error-Codes for all Parse/Write-Exceptions and Errors.

[flappingeagle]

Like asked at Stackoverflow:
https://stackoverflow.com/questions/50911195/can-woodstox-error-messages-be-customized

Cite of Staxman:

addition of formal error codes in Exceptions seems like a good improvement (Stax spec/API does not have those, but Woodstox implementation types could, either directly, or as tag interface). One potential challenge might be that of how to templatize things (how to add pertinent pieces of information within message). But adding error codes seems like a good start.

I will also take a look at the codebase and see if i can provide a pull-request for this.