add TestInputParser and InputParser
simplify test case
InputParser: add a constructor parameter
minor refactor
implement testReadFirstField()
rename TestInputParser to InputParserTester
implement FieldTester::testConstruction()
implement Field:: lines() and columns()
implement testInitialSquareStates()
add PositionTester and Position
refactor Field to use Position
Field: handle negative sizes
refine naming
make InputParser operate on streams instead of filenames
implement reading size of Field
add missing test cases for Position
wire in forgotten test :S
Field: implement non-volatility
implement Position::isInBox() and improve exceptions
Field: accept only positive size and test isMineAt()