Issue #16: Adds parse_options::require_document.
Issue #16: Adds the ability to json_checker to use strict and non-strict checking.
Issue #16: Adds parse_options::comma_policy for trailing commas in arrays and objects.
Issue #16: Adds parse_option::encoding::utf8_strict to check for non-printable input characters.
Issue #16: Add the ability check the maximum depth of a structure.
Issue #16: Adds parse_options::number_encoding to check for leading zeros.
Travis CI: Adds release testing and only publish Doxygen on the last environment.