empty @inner tag (in wrong place?) crashes very ugly

I developed an AMD module that uses an internal function. I thought it would be nice to tag the documentation of that function with the @inner tag (though it might not be entirely valid). That crashes documentationjs without clean error. Adding some text on the same line after @inner removes the crash.

Code sample:

```
define([], function() {
DoSomething();

/**
* My Object of Documentation Desire
* @exports myObject
*/
var myObject = {};

return myObject;

/**
* DoSomething - Might do something
*
* @return {boolean} Did we really do anything?
* @inner
*/
function DoSomething() {
return false;
}
});
```
Error Message:

```
documentation build src/documentationbug.js -f html -o docs2/
/usr/local/lib/node_modules/documentation/lib/commands/build.js:66
throw err;
^

TypeError: Cannot convert undefined or null to object
at hasOwnProperty (native)
at /usr/local/lib/node_modules/documentation/lib/hierarchy.js:68:27
at Array.forEach (native)
at module.exports (/usr/local/lib/node_modules/documentation/lib/hierarchy.js:38:12)
at buildSync (/usr/local/lib/node_modules/documentation/index.js:221:5)
at /usr/local/lib/node_modules/documentation/index.js:147:16
at /usr/local/lib/node_modules/documentation/lib/input/dependency.js:63:5
at ConcatStream. (/usr/local/lib/node_modules/documentation/node_modules/concat-stream/index.js:36:43)
at emitNone (events.js:72:20)
at ConcatStream.emit (events.js:166:7)

```