Enable "i_" JSON tests

[joeslice]

According to https://github.com/nst/JSONTestSuite, test cases whose filename begins with "i_" should result in behavior at the parser's discretion.

These tests were added in #19 but were left skipped to be addressed in this issue.

The scope of this issue is to:

• Decide on behalf of KSON how these tests cases should be handled (parser error or no parse error)
• Enable "i_" tests and make them pass or assert failure as appropriate
• For any remaining skipped "i_" tests, file a follow-on issue to address them, or document why they are permanently skippable

[dmarcotte]

The remaining i_ tests to handle are enumerated in JsonTestSuiteEditList. Once those are all eliminated (or documented with why they will be forever-skipped), this can be closed

[dmarcotte]

Done! 38e9753