Fixed padding on "n/a" in location which lacks source code
Added visitor
Replaced "n/a" with "not available" and "no source code"
Fixed bug in JSON parsing
Turned pretty printer into a ValueVisitor
Moved all introspection into Introspection class
Moed subValues() method into visitor
Use a visitor pattern for JSON unparsing and get/sets for parsing
Moved more rendering into PrettyPrinter class