hdf5: Added params for data type (min, max, mean and quartiles)

Hi,

I've added some features like this one which are useful for us. This feature introduce an optional parameter, named "type", when we want to access the hdf5 api. It gives us access to the minimal, maximal, mean or quartiles values between the start_time and end_time.

Best regards,

Ludovic Schoepps.