Adding setup.py so it is installable via pip and other packages

`pip install git+http://github.com/GoogleCloudPlatform/endpoints-proto-datastore.git#egg=endpoints-proto-datastore`
Changes per comments from upstream on PR

* Version is now 0.9.0
* Use fq package names
* Remove ### comments since they weren't really needed
Change desc to clearly advertise that this is a library to work with
Google Cloud Endpoints
Add trailing newline since PyCharm stripped it
Merge pull request #99 from KAPx/master

Adding setup.py so it is installable via pip, etc