it used to be a typedef to gpointer and actually was a cmsHPROFILE.
Change its API to be more "standard", remove the public close()
function. The object caches both the cmsHPROFILE and the data/length
ICC blob, so conversions between the two become obsolete (simply call
get_lcms_profile() or get_icc_profile()).
Adapt everything to the new API, but port it in a naive way for now,
the code doesn't take advantage of the new possibilities yet (like
refcounting).
Which returns a GimpColorTransform to transform a GimpColorManaged's
pixels to a GtkWidget's color space, using a GimpColorConfig's
settings. This is *unfinished* API and in the end will enable simple
display color management for the app, libgimp and plug-ins.
Move some functions from libgimpwidgets/gimpwidgets.[ch]
and from app/widgets/gimpwidgets-utils.[ch]. Newly add
gimp_widget_get_color_profile() which is extracted from
modules/display-filter-lcms.c.
