Implement Eq and maybe Ord for AugmentScriptSet

[crlf0710]

Eq is necessary for using in hashmaps, and for rustc reproducible builds, it will be even better if it can also implement Ord so we can use it in BTreeMap.

[crlf0710]

Eq is added in #17 . Not sure yet about the Ord part, maybe we can see whether we can sort the Span instead as a workaround.

[crlf0710]

It turns on Ord part is not needed. closing.