Use Array#last rather than negative index.
Add usage example.
Explicitly define listener events.
More Array#last.
Specific json in example.
Use keys stack instead of ObjectNode.

Reduces the number of garbage collected objects during parsing by not
creating ObjectNode and ArrayNode containers.
One definition per line.
Remove parens from assert DSL.
Add tests for non-object and array values.
Add whitespace around separators.
Add test for real json document.
Remove parens from assert_equal.
Unroll test loops.
Unroll array test loop.
Add skipped tests for value documents.
More specific test description.