There is currently no property widget which just creates a
GimpSpinButton with a label. Just as the GimpScaleEntry was needed, this
one is as well.
I am creating a GimpLabeled abstract class which will represent various
widgets with a label. While this may seem a bit over-engineered for such
a basic feature, this will actually bring some consistency and a common
parent. In particular this can be used to get the GtkLabel with a common
interface to add them all in a common GtkSizeGroup when generating
dialogs automatically, hence make dialogs with properly aligned labels
and edition widgets.
Similarly to GimpScaleEntry, this is meant to replace usage of
gimp_color_scale_entry_new() by having a proper widget. This is a child
class of GimpScaleEntry which simply replaces the GtkScale by a
GimpColorScale by adding a GimpScaleEntry class method to create the
scale widget (only restriction: it must be a GtkRange subtype).
This also triggers me to rename gimp_scale_entry_get_scale() into
gimp_scale_entry_get_range() (as well as the 2 plug-ins already using
this function).
libgimp is anyway processed at the very end after all other libgimp*
were built. This way, it also fixes#3746, by removing the $(top_srcdir)
everywhere from introspected files, hence making the build work again
with older automake.
Only leave behind gimpcolorscale, gimpcolorscales and gimpcolorselect
for now. There are some GI compilation errors and I don't have the time
right now to look into it. Most of libgimpwidgets is available to GI
bindings now anyway.