Fix: Multiline-descriptions for “@param”, “@return(s)” and “@throws” jsdoc-tags do not work

Hi everybody,

first of all - thanks for your hard work so far :+1: 

The regular-expresions for “@param”, “@return(s)” and “@throws” jsdoc-tags in `lib/doc_tags.coffee` have been bound to a single line description:

    parts = value.match /^…$/

Therefore multiline-descriptions break the process and throw an exception, as multiline-input does not match and returns **null**.

An example I stumbled upon (the method's `template`-parameter description):

    ##
    # HTML template processor. … (shortened a bit)
    # 
    # @param  {Context} context  Context created from the input data object.
    # @param  {Element} template DOM node of the template. This will be processed
    #                            in place. After processing, it will still be a
    #                            valid template that, if processed again with the
    #                            same data, it will remain unchanged.
    # @param  {Object}  options  Options passed to `Processor.create()`.
    # @return {void}
    process: (context, template, options) ->
      …

My solution to make this work is trivial:

    parts = value.replace(/\s+/g, ' ').match /^…$/

In my setup it does not break anything and there seems to be no objection to go this way.

What do you think ? I'd like to use multiline-descriptions and would be glad if you pull my (a little bit polished) solution or give me a hint, what alternatives I might have missed.

(Hint: This is the second pull-request for this issue, as I messed up the original request …)