LPS-47094 Tests for MapUtil class

Hey Manu,

We have organized a workshop session in the hungarian office for the coders to learn and code junit tests, and this is the first outcome. @peterborkuti has implemented a set of tests for the MapUtil. I've checked it for source formatting, but I wanted you to review it as well, since you are the "test guy" :)
This is nothing fancy, unit test, not even integration.

Thanks,

Máté