Parse tag strings with Markdown

[jugglinmike]

Dox was just recently updated to parse Markdown in tag descriptions, but it does not (currently) do the same for the string property of tag objects. (The string property is used in place of description for tags which do not include a "type" specifier.) Here's an example usage:

/**
 * This option enforces the consistency of quotation marks used throughout
 * your code. It accepts three values: `true` if you don't want to enforce
 * one particular style but want some consistency, `"single"` if you want to
 * allow only single quotes and `"double"` if you want to allow only double
 * quotes.
 *
 * @deprecated JSHint is moving away from enforcing stylistic concerns. Check
 *             out [the JSCS project](https://github.com/jscs-dev/node-jscs)
 *             for similiar functionality.
 */

Note that I've had to special-case the alias tag. I think this makes sense, but I'd welcome input from a maintainer.

[jugglinmike]

Is there anything more I can do to help move this along?

[evindor]

Thanks and sorry it took so long :)

[evindor]

Will make a release after we handle #143 in next few days

[jugglinmike]

No problem at all. Glad I could help!