Enhancement:  support home storages

Reva did not have any functionality to handle home storages.
These PRs make that happen. 

https://github.com/cs3org/reva/pull/562
https://github.com/cs3org/reva/pull/510
https://github.com/cs3org/reva/pull/493
https://github.com/cs3org/reva/pull/476
https://github.com/cs3org/reva/pull/469
https://github.com/cs3org/reva/pull/436
https://github.com/cs3org/reva/pull/571
