Adding tests for fix #640

Without the fix, we get the following when running ./jsdoc -T
    Failures:

    jsdoc/name splitName

      1) should allow default values to have brackets
      Message:
        Expected '[path=["home",' to be '[path=["home", "user"]]'.
      Stacktrace:
        undefined

      2) should allow default values to have brackets
      Message:
        Expected '"user"]] - Path split into components' to be 'Path split into components'.
      Stacktrace:
        undefined

      3) should allow default values to have brackets inside strings
      Message:
        Expected '[path=["Unmatched' to be '[path=["Unmatched begin: ["]]'.
      Stacktrace:
        undefined

      4) should allow default values to have brackets inside strings
      Message:
        Expected 'begin: ["]] - Path split into components' to be 'Path split into components'.
      Stacktrace:
        undefined

    Finished in 5.704 seconds
    870 tests, 2331 assertions, 4 failures

These tests pass with the fix