@apiPrivate parser returns string, causing strange data in output.

[nomoon]

The @apiPrivate parser currently returns a string:

apidoc-core/lib/parsers/api_private.js

Lines 1 to 3 in c32ada3

	function parse() {
	return 'private';
	}

When documentation is generated with the --private flag, this results in the following JS/JSON data in the entry:

{
    ...,
    "0": "p",
    "1": "r",
    "2": "i",
    "3": "v",
    "4": "a",
    "5": "t",
    "6": "e",
    ...,
}

Looking at other similar parsers, it seems that the correct output of the parse() function should be an object, like this:

apidoc-core/lib/parsers/api_deprecated.js

Lines 15 to 17 in 2069f4e

	return {
	deprecated: true
	};

[nomoon]

#112 was merged, so I'm going to close this. Thanks!