Implement invoice calculation logic

Added multiple new (unimplemented) methods in services.
Also removed people count from Lease, it made no sense, it's actually a
measurement.
Service - energyPrice, Invoice typo fix
EnergyTypeService unit test
create a update metody vrací DTO objekt
remote server pro testy
Change price intervals to whole months
Some minimal work on lease
Change all date fields to YearMonth
Add custom user type for YearMonth

The one from jadira uses serialized instances and we need to compare
dates.
Right now the user type is set using annotation in every entity, should
find a nicer way.
část service unit testů
přesun domů
Non working version
Fix test deployment
Small changes to test deployment
Clean up entities
wtf v lease service testu
wtf v lease service testu2
oprava wtf v testu (chyba konverze DTO -> DAO)
Implement EnergyPriceDao with simple test
Small fix to InvoiceDaoImpl