Changed variables name to be more meaningful

The following changes have been done in the code:
RR -             numberOfRows
CC -            numberOfColumns
ORDMAX - sizeOfHelperArray
JPRIME -    numberIsPrime
N -              positionInHelperArray
MULT -       helperArray
J -                oddNumber
ORD -         primeNumberToBeSquared
SQUARE -  nextSquaredPrime
C -              i