BLD: Correctly install package_data dirs.

Are the Travis builds passing right now? For me, I can't build. 

```
python setup.py build
```

Fails with

```
error: can't copy 'pysal/examples/snow_maps': doesn't exist or not a regular file
```

The `example/*` glob matches the directory and can't copy it over like a file. This fix adds the globs for each file type and the directories. Won't work if there are every any nested dirs within the subdirectories.