More reliable data synchronization (Version 2)

synchronization loop reworked to always look back further than a fixed time window and instead fetch all updates since the last synchronized bolus
consequently, removed a bunch of parameters for synchronization (dateFrom, dateTo are now automatically determined)
import of basal rate from pump settings is no longer optional
logic has been adapted to eagerly publish treatments / records to nightscout (and delete them later if necessary). E.g. carb corrections will be synchronized to nightscout as soon as they appear on diasend. If it later turns out, the carbs actually belong to a meal bolus, the carb correction will be deleted and replaced by a meal bolus
individual handlers to send / retrieve data from / to nightscout replaced by one interface to interact with nightscout.
- arguments nightscoutProfileLoader and nightscoutProfileHandler of startPumpSettingsSynchronization replaced by nightscoutClient.
- argument nightscoutTreatmentsHandler of startSynchronization / syncDiasendDataToNightscout replaced by nightscoutClient
- argument nightscoutEntriesHandler of startSynchronization / syncDiasendGlucoseToNightscout replaced by nightscoutClient

Addresses #18

burnedikt / diasend-nightscout-bridge