[MAP]Graphical stamps on documents.

This patch adds 11 art assets for the different stamps of the game to replace the text only stamps that we have at the moment.
I also separated the default stamp from the Quartermaster and Law office stamps.
Stamps are now displayed as a single line, which should wrap nicely every 3 stamps with the default html window size.

NOTE: The map edit only replace the generic stamps in the qm office and law office by their unique counterpart.