Unexpose gparseJson

[bergmark]

in #653 @Lysxia said

It's unfortunate that gParseJSON is exported in the toplevel modules Data.Aeson/Data.Aeson.Types. Users should really not depend on these Generics internals. It would be a good idea to hide this at some point [..] so we can just remove gParseJSON.

We should at least wait for #653 to be merged, then we can also rename the new gparseJson' to gparseJson at the same time. But I'd also like to avoid doing a major release since we had one recently and this change is mostly hygienic.

I wonder if anyone is using the current gparseJson? If they are they would probably like to use gparseJson' instead. Some investigation on aeson usages on hackage/stackage would be nice.

[Lysxia]

Github-searching for gParseJSON returns 230 or so results, and almost all occurences are either gparseJSON from generic-aeson (that could be filtered out if Github search were case-sensitive) or in duplicates of the FromJSON module, so it was quick to go through all of them.

The only two actual matches are one inactive repo (unreleased) that just reexports it without using it, and a more active one that could certainly do without it (and that file is located under a directory named deprecated/...).

[phadej]

Let's do this for 1.5