More possibly useful abstract methods to Activity

getDates() and getBeginDate() make *sort of* sense for SingleActivity, too.

More importantly, now we're able to get the relevant date data out of
any Activity object (even if we don't know if they are Single or
WeeklyActivity objects)
rudimentary JSON file reader class structure

we'll use Jackson for this
writin tests for json dump reading

copypasting a target json dump string into Netbeans was surprisinly
straightforward
comments for the test class
restructuring json dump reader test
TDD: basic tests
Tests; also beginning fleshing out file io methods
slightly more sensible path params? idk
Pondering the usefulness of ActivityGroup
 the readCourseModuleDump method
Changed JSON timestamp format
Getting rid of a test that won't work anytime soon
Implemented CourseModule dump reading in FileHandler

I've got this nagging feeling the implementation is more-or-less
half-assed, but anyway:

* the json file is opened with mapper.readTree(), we got a rootNode
* using that as starting point, the JSON tree is traversed

Needs more testing.
Updated pit and cobertura conf (testing fileio)

lukkari.fileio package is now included in the reports
whoopsie!

one date field remained in the old format in the test module.json
TDD: more tests...
Fixed test
Testing parsing Groups from CourseModule dump
more json parsing tests
Implementing exam parsing

also removed unnecessary sout