add support for microsecond periods (GH2145)
(Continues #2145)

Alrighty. This should be fine. There may be a few formatting changes that I rolled back through the git diff / apply patch, but all not-skipped tests pass so I figured it wasn't a big deal. Here's what I did to fix the problem, which was continually merging with upstream:

``` shell
function get_my_commits {
    local curdir="$(pwd)"
    cd "$1"
    # %n adds a newline in addition to the file name
    # sed removes blank lines here
    # sort -u sorts and removes duplicates lines
    git log --name-only --pretty=%n --author=Phillip 0eeff..master | sort -u | sed '/^$/d' 
}

old_pandas=/path/to/evil/pandas/merge/of/death
new_pandas=/shiny/new/checkout/of/pandas

get_my_commits $old_pandas | while read file; do
    # some boolean tests to filter out setup.py and missing files between versions
    diff -pu "$old_pandas/$file" "$new_pandas/$file" | patch -p0 "$new_pandas/$file"
done
```

Needless to say I won't be doing any more merging of upstream into my branch. Thanks to those who helped me out here.

@cpcloud, I saw an emacs related commit in the original pile. 
If you're an emacs user, you might like to look into [magit](https://github.com/magit/magit). 
It has fantastic interactive rebase support and I use it all the time.
 @y-p Cool, yeah I saw your comment before. Thanks! I've used magit a little bit (comes with emacs-starter-kit, I'm definitely a huge emacs fan), but I'm sort of a command line junkie and I haven't spent the time to get used to magit yet. After this experience, however, I will start using it.
 Quick question: if I `git pull --rebase upstream master` on this branch will that add more commits to this pull request, i.e., will it be problematic?
 If you just add commits to the branch and push, they'll be added to the PR.
If you do a rebase,you'll need to do "git push -f" since you'll be clobbering the 
existing commits. Forced push is usually a no-no but usually fine for pull request branches.

Make sure you know how to backpedal if the rebase has conflicts and you make a mistake,
or use a temporary branch.
 Is this going to make it into 0.11?
 no, and I think #3060 swallowed it.
 @y-p is correct. I think @wuan has a more general solution to this issue. Should I retract the pr associated with this issue? 
 I'm going to close and look at merging #3060 
