Context implementation classes are created by spring
DataUnitMerger interface, base class and class merge into single class,
there is no need to have them separate any more
Possibility to terminate backend from console by 'exit' cmd
Log information about used config.properties file #233
EmailSender can be configured in terms of smtpHost, smtpPort and ttl
Added warning for missing output DataUnit, close #115
Merge branch 'master' of https://github.com/mff-uk/intlib.git