chore(project): add jshint config
feat(common): encapsulate xml specifics

This commit updates to the latest version of moddle and pulls all xml
specific code to commons module (previously found in moddle).

It performs the following changes:

* align structure with moddle (index.js)
* remove moddle stack in favour of tiny-stack
* encapsulate xml specific configuration in the "xml" property of a
package descriptor

BREAKING CHANGE:

Due to the encapsulation changes, the package descriptor alias field has
moved into the XML property:

{
   "name": "DataTypes",
   "uri": "http://datatypes",
   "prefix": "dt",
-  "alias": "lowerCase",
+  "xml" : {
+    "alias": "lowerCase"
+  },