POT-Creation-Date is set to match the timestamp in 5.7.2beta which
in the Translation Project is known as 5.8.0-pre1. The strings
haven't changed since 5.7.1alpha but a few comments have.
This is a very noisy commit, but this helps keeping the PO files
similar between the Git repository and stable release tarballs.
In the past this wasn't done before releases; the Git repository
just contained the files from the Translation Project. But this
way it is clearer when comparing release tarballs against the
Git repository. In future releases this might no longer be necessary
within a stable branch as the .po files won't change so easily anymore
when creating a tarball.
I made a few white space changes to these without getting them
approved by the translation teams. (I tried to contact the hu and
zh_TW teams but didn't succeed. I didn't contact the zh_CN team.)
