#17, #18, #19, alpha
fix repo impl
#17 implementation of MeasurementDataRepository
add missing methods to MockMeasurementDataRepository
added Predicate for DataLimit.last
optimalization
Code improvements
Merge branch 'developer-przemek' into develop

Conflicts:
	DSM-monitor/src/main/java/pl/edu/agh/dsm/monitor/measurement/mocks/MockMeasurementDataRepository.java