Auto generate module header

https://trello.com/c/aFzHsV87

This commit modify the way in which module header is created. In past the
Header class loads entries from header.html file which was inside bundle.
Currently, this class searches css and js files in webapp/css, webapp/js
and webapp/lib folders and creates appropriate header for the module.
Added yuicompressor plugin into build process

https://trello.com/c/aFzHsV87

The yuicompressor plugin in each module finds JS files and compresses them.
Then the plugin aggregates them into single file with artifactId name.
The plugin does the same with CSS files.