Update XSpec to v2.0.7

[AirQuick]

This pull request updates the bundled XSpec to v2.0.7.

XSpec v2.0 has some new features which aim to ease integrating XSpec into this oXygen-XML-editor-xspec-support plugin. 5e865f6cf3937e59dff3116a93013d90cf65fbb3 and 4a454e3959fa15088504deda3c4bbc6b547caa10 take advantage of it:

• Some patches are no longer necessary. 5e865f6cf3937e59dff3116a93013d90cf65fbb3 replaces them.
• XSpec is able to test XQuery modules, but the oXygen-XML-editor-xspec-support plugin did not support it. It's now easier to support it. 4a454e3959fa15088504deda3c4bbc6b547caa10 implements it.

XSpec v2.0 has some internal changes as mentioned in xspec/xspec#1121. 6b6bef85c7845a64d473ce6fd498372e08826a46 reflects them on the tests.

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Closes #38

[AirQuick]

@AlexJitianu Thanks for looking into this. It would be nice if you could merge this.