Allow the presence of inline tags for a `@returns` tag that does not have a type spec.

A doclet with this sequence used to cause jsdoc to fail:

    @returns The caller can pass this value to {@link blah}.

jsdoc would complain about not being able to parse `@link blah`. It appears that it treated the link as a type specification. The presence of a type at the beginning of the tag's text would hide this problem so that this would parse fine:

    @returns {Foo} The caller can pass this value to {@link blah}.

Because `{Foo}` would be treated as the type spec and `{@link...}` would convert normally.

I've added a new test that fails if run against the version of jsdoc currently in the master branch. Post-modification of the code base no tests are failing.