Minimize includes in head.jsp

https://trello.com/c/aFzHsV87

This commit adds ability to set order of CSS and JS files in final file
and in header templates. The aggregation and generation header process
is in GenerateHeader.groovy script.

A user can set order by creating yui-order.js file inside src/main dir
inside module. The JSON can contains 3 properties related with folders
in webapp folder: lib, js, css. Each of these properties are array of
objects with properties:

* path   - path to file in the key folder
           e.g: "js":[{path: 'app.js'}] -> webapp/js/app.js
* order  - on which place the file should be placed
           (values: numbers, 'first' or 'last;)
* after  - after which file the file should be placed
* before - before which file the file should be placed

Only one of properties (order, after, before) should be used. Firstly
script tries to use order property, next it tries to use after property
and in the end script tries to use before property.

Example file is in server-bundle module.

Change-Id: Ie7cbdc86b0b261d0726dc4f0f7ce05579c1f8e3d