Cloudio-endpoint-python

Implemented enhancements:
- Changed behaviour when Endpoint is ready. Speeds up connection
Fixed bugs:
- Bugfix in utils.ResourceLoader

Fixed bugs:
- Improved reconnection procedure. Related to issue [16](https://github.com/cloudio-project/cloudio-endpoint-python/issues/16)

Fixed bugs:
- Better fix for issue [16](https://github.com/cloudio-project/cloudio-endpoint-python/issues/16)

Fixed bugs:
- Fixed issue [16](https://github.com/cloudio-project/cloudio-endpoint-python/issues/16)
Other changes:
- Allowing again to provide username (with/without password) even if
client certificate is provided

Fixed bugs:
- PersistenceDataStore now working in Python 3

Implemented enhancements:
- Moved version string into _endpoint_ package
Fixed bugs:
- In case client certificate is provided, username and password are no more needed
- set actions now also working in Python 3