Remove the inheritance of JPetTaskInterface for JPetTaskIO
Remove the inheritance of JPetTaskInterface for JPetTaskIO

Some fixes to JPetTaskChainExecutor also done.

wkrzemien/j-pet-framework,wkrzemien/j-pet-framework,wkrzemien/j-pet-framework,wkrzemien/j-pet-framework,wkrzemien/j-pet-framework