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.
and use it to compute influence with a gaussian like curve
implementation use a lookup table to speed things gimpwarpoptions: add
a hardness property and UI