I have just deleted 6.4 releases on GitHub and pypi

[Edward K. Ream]

Imo, deleting the "published" versions of 6.4 should be safe enough and will reduce confusion in the long run. These deleted versions were not widely publicized.

I'll create a new 6.4 on GitHub late this afternoon, after we have all had at least some chance to test the code.

I'll create a new 6.4 on pypi tomorrow.

Edward