Identifiers from other databases require update

[GwennyGit]

The BiGG identifiers I have in my model were used by ModelPolisher to add further annotations, like MetaNetX identifiers as well as EC codes. ModelPolisher uses the BiGG Models knowledgebase for that.

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Update for MetaNetX identifiers
Thoroughly analysing some of my model's MetaNetX identifiers revealed that at least 165 identifiers were deprecated. These MetaNetX identifiers correspond to the URIs provided on the BiGG database page of the according BiGG identifier URI.

Hence, an update of the MetaNetX identifiers would be required.
(This problem was also already stated in issue #413.)

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Update for EC codes required
For the EC codes at least the following one is deprecated in my model which also corresponds to the URI provided on the BiGG database page of the according BiGG identifier URI.

BiGG URI	EC code URI	New EC code URI
https://identifiers.org/bigg.reaction/NADH17pp	http://identifiers.org/ec-code/1.6.5.3	https://identifiers.org/ec-code:7.1.1.2

Hence, an update of the EC codes would be required.