Show markdown description text on item detail page

* Update build process to *not* copy over prerendered pages during a
  regular build (only during a `dist` build)
* Add dependency on npm "markdown" package and include it in the
  scripts loaded in the default layout
* Update the Item model to be able to load from a *.cg file
* Add an ItemParser to process the `item.cg` file
* Update the general parser to be able to work with HereDoc-style
  text blocks
* Add a markdown-specific stylesheet
* Add a sample of the `item.cg` file format (Advanced Crafting Table)

src/coffee/models/item_parser.coffee

@@ -0,0 +1,19 @@
+###
+Crafting Guide - item_parser.coffee
+
+Copyright (c) 2014-2015 by Redwood Labs
+All rights reserved.
+###
+
+VersionedParserBase = require './versioned_parser_base'
+ItemParserV1  = require './parser_versions/item_parser_v1'
+
+########################################################################################################################
+
+module.exports = class ItemParser extends VersionedParserBase
+
+    # VersionedParserBase Overrides ################################################################
+
+    _createParsers: (options)->
+        return result =
+            '1': new ItemParserV1 options