Fix #490

[paf31]

@garyb @joneshf Does this look ok? It allows us to make binary distributions which copy the Prelude to the user's home directory or the XDG config directory.

@joneshf I was thinking as well, maybe what we could do with XDG is to turn support on/off based on a cabal flag. What do you think?

[coveralls]

Coverage increased (+0.01%) when pulling 8bf954a on bindists into caa1dc6 on master.

[joneshf]

I think since people are still having issues with the xdg library, we should just can it all together like in the last PR you did, until whatever install problems are fixed with the library, or someone writes a new one. I mean, this isn't doing "The Right Thing" on osx I don't think. Also, I think I might have said XDG_CONFIG_HOME before, but I think prelude belongs in XDG_DATA_HOME, since it's something that shouldn't be deleted.

Maybe the xdg library problem is actually not an issue if we're shipping binaries anyway?

In any case, I think it looks good enough to merge. 👍 Especially if it gets binaries for other platforms!

[paf31]

@garyb Would you mind giving this a quick test on Windows please, if you have time? I've only tested on Mac and Linux. Thanks.

[garyb]

Sure thing.

[garyb]

Yep, it's all good. As a test I moved the prelude.purs around and it resolved from ~/.purescript etc. as intended too.

[paf31]

Excellent, thanks.