New parameter for OPF spec conformance

[Asbjoedt]

Hi!

I think it would make sense to have a a parameter, that the user can specify which version of the "OPF Spreadsheets Preservation Specification", that the user wants to validate against.

Initially, the validator will only support version 1.0, but I think it would be good to add the framework for implementing other versions of the spec i.e. 1.1, 2.0 and so on now.

Parameter could look like -v1.0.

This parameter will then validate all the requirements and give corresponding errors, warnings and information.

Be aware, the versioning here is not the OASIS file format spec version. This version is handled through the abovementioned spec, which has requirement ODS_2, which will specify the file format version.

Additionally, I think it would be a good feature to enable solely OASIS file format spec version validation. This could be a parameterless validation. So not giving any other argument than the filepath, would then solely check the file format spec and it would do so against v1.3 of the spec. If we consider to have versioning of this also, we could revise it so:

Policy validation -policy1.0
Solely file format standard validation -standard1.3

But using both of these parameters at the same time would be mutually exclusive if you wrote i.e. -standard1.2, because the policy specifies v1.3. Using both argument should then lead to an argument error.

What do you think about this? What is the best implementation? Will it be confusing to have two parameters,that targets two different and potentially mutually exclusive specifications?