Minor changes

after merge with TestEx02
focalVariety done!

already tested
Add java doc
Implement Ex03 .. DONE

start to test
Test Ex03 Complete!

It can be submited...
Add javadoc for zonalMinimum
Finish implement Ex04

Let test :smiley:
Fix and test done!

Let's submit!
Ex05 Done!

Not so difficult. Currious for the final project!
Merge pull request #8 from nntung/Tung-dev

Tung dev .. Ex 05 OK