Cleanup: simplified serializer initialization
Merge pull request #80 from julen/serializer-init

Cleanup: simplified serializer initialization
Extract PO catalog managment to its own class. Reduce duplicated code and apply separation of concerns
Cleanup: Remove unused image
Cleanup: Move SVG images to img/svg/ directory
Recover the comment explaining the comment modification

It was dropped in 9bc9fd0d, and it is easier to understand the code
with the comment.
Deployment: Update css paths after moving all CSS files to css/

Followup for 21e1c495.
Deployment: Update images paths after moving all images to img/

Followup for 96ce0c70.
Rearrange and cleanup code to ease refactoring to common function
Cleanup: Refactor into common function