Initial setup of BuienRadar module
TODO: dashi connection handling
DONE: Getting the data from buienradar and parsing it
      Calculating the rain at a time in the future
      Calculating the maximum rain between now and a time in the future
Changed the register method to send the rpc key back with the registration for each sensor.
DomosTime editted to parse this rpc key from the dict and act on it
removed debug print statement
revamped module structure and module rpc structure

Modules now support multiple rpc's of the same type. This means that the database relation between a sensor and module has moved to sensor and modulerpc. Furthermore, a module gets a modulerpc key with the registration reply for each sensor it gets.
Modules are autoloaded. This enforces the directorystructure of $module/$module.py The $module.py is loaded and the start() function in this module is executed after importing the module. The stop() function is meant to be called at shutdown to clean up anything
that the module was using.
Merge branch 'multi-addrpc'