Added 5 new methods & general improvements

Added new methods:
 - getCountry: get random country
 - getCountryShort: get random country abbreviation (2 chars) 
 - getNationality: get random nationality
 - getOccupation: get random occupation
 - getHexText: get random hex string with given length

Some general improvements:
 - Updated pom.xml to use latest version of maven plugins and dependencies
 - Use clean-up/reformat code to change tabs into 4 spaces and wrap after 80 chars
 - Some typo's fixed
 - Added missing javadoc