BUG: GH10160 in  DataFrame construction from dict with datetime64 index
closes #10160
closes #9456
 where `DataFrame/Series` construction from nested `dict` with `datetime64` index returns a `DataFrame\Series` of `NaN`s.

pls rebase on master and repush had an issue in the builds
 ok, this overlaps with the issue in #9456 , currently with a PR of #9924 to fix
 lets define a function someting like:

put in `pandas.core.common`

```
def _dict_compat(d):
    return { _maybe_box_datetimelike(key) : value for key, value in compat.iteritems(d) } 
```

then can use in both places.
 @kawochen looks good so far. can you add in tests/fix for #9456 ?
i'd like to fix both in this PR (this PR can then supersede #9924)
 Sure I will do that.
 @kawochen any progress on this? (e.g. incorporating the Series fix as well)
 Yes I did that a few days ago. I squashed the commits when I rebased (I'm new to github, maybe I shouldn't have?). 
 merged via https://github.com/pydata/pandas/commit/821542fb1dfd55b0e0d25e55eb4fee6555d01cbd

thanks!

FYI, when you push again, I don't know you updated (e.g. there is no notiifcation on that, only on a new PR). So if you want me to have a look, ping!
