allowing newer versions of pycrypto
replacing the custom "Dialog" tool by click
moving requirements into a single file
Code refactoring:

* `local_server` and `common` have been moved to the `hestia` sub-directory
* `hestia-server.py` now accept command line options
* `hestia.conf` support has been dropped
* the server doesn't handle commands anymore: the protocol will be changed soon
* database creation is now handled by `hestiactl.py`
* exceptions have been moved to a dedicated file