Policyd-rate-limit

Fixes:
- Force flush to stderr when writting in the main program loop
- Some postgresql fixes
- Display a nice error message if trying to use a db backend not installed
- Use a bigint (signed integer on 64bits) for date as unix timestamp
- Call db optimisation on --clean

New:
- Add the possibility to send email report about who reach limits

- Update init script according to debian policy
- Catch PermissionError on configuration files
- Catch database initialization errors (exit value 7)
- Add possibility to get which configuration file is being used

- Add rst man pages to pypi tar releases

- Put action_fail error message in the configuration
- Handle multiple connections
- Rename --get_config to --get-config and give to possibility to get dicts
- Add possibility to specify a config file using --file or -f
- Add rst template for generating man files

- If database backend is sqlite3 and the db directory do not exists, create it
- add Makefile to pypi releases

Only MySQLdb Warning class is a Warning subclass, thus we only can ignore MySQLdb warnings.
Has only MySQLdb raises warnings it is ok.