Merge pull request #1 from gnedov/forTests

JUnit ver.4.x tests added. TODO: add more test.
Added test/com/agn/dioClass/ArrayOperationTest.java.
_> Status OK.
modify printOutInCol() method:
- output in column using Formatter()
apply code review patch by [wasman]
fix after code review:
- add and use static import EnumOperationType.
fix after code review:
- in interface all methods are public by default.
minimal cleaning and formatting code