Removed unnecessary beginJob/endJob methods

In order to facilitate possible conversion of the modules to stream based
modules, we must remove the beginJob/endJob methods (since they are
not supported by the default stream implementation). This commit removed
empty/unnecessary beginJob/endJob methods. In the cases where the methods
were being used, they were left alone but the 'override' declaration was
added to ensure that if the module were converted to a stream module the
compiler could catch the fact that beginJob/endJob are not defined in the
new base class.
Merge pull request #2754 from Dr15Jones/removeEmptyBeginEndJob

Multithreading framework -- Removed unnecessary beginJob/endJob methods