and remove lots of labels from calls to gimp_prop_foo_new(). Also
had to manually remove some unwanted labels that are now added
automatically, fixes bug #761880.
instead of passing N_()-strings; and remove gettext() calls on these
strings when using them. Reduces complexitx, and fixes double- and
untranslated strings. Also enables to treat properties of GIMP and
GEGL objects the same way, which was totally broken before.