refs #6447 Changed the order of operations in the test suite suggested

by tester. Though I believe the previous order was more suitable highlighting the internal variables used by the suite right from the beginning.
refs #6447 Made better comments around (from) commented piece of code

in BoxController.cpp == operator. Comments are necessary to highlight the assumptions, made when defining the operator.
refs #6447 Syntax improvement.
Merge branch 'feature/6447_UnitTest4MDBoxTree' into develop