Test legends

#310 

In this PR:
1) Test systematically all the legends in all langs
2) Remove obsolete legends ( checked with @AFoletti )
3) Fix some pdf legends
4) Do not use bgdi_created column (some were empty) to determine the layer timestamp ( @ltclm told me it makes no sense and I agree )
5) Fix treasurehunt legend

Finally:
Some layers that are only found in "swissmaponline" don't work.
We simply don't have those layers info in view_bod_layer_info_{lang}.
As a result the legends don't work.

I checked in their application and they are already using RE3 services for legends and they don't work.
@ltclm What would be the best approach? simply add those layers in the view?

At the moment they are hardcoded in the test.

FYI: It takes around 45 sec to test all legends...