Fix Double defined msgid's in po-files.

Unfortunately due to previous commit in simplying the code, which then caused an incorrect commit:
'Update translations for layers menu popup which no longer have to start with '/''
SHA1:33a5209f18fdddfa011eabc3d4834cc23bef5955.

Which aligned the translation to the code. However Po files don't allow repeated text strings as ids.

Simply remove the secondary copy in most places and for the da translation copy the texts into the first place.

Signed-off-by: Rob Norris <rw_norris@hotmail.com>
Import Launchpad translation updates for Asturian language

Translation created by Xuacu Saturio