Icons tweaked #4469

- The "light" icon theme is now a little lighter, to increase contrast.
- Toolbox icons are now small.
- Buttons:
  - Buttons without labels which use icons as their only source of info regarding what the button does (e.g. the white-balance pipette button) use normal-sized icons.
  - Labeled buttons which use icons as an auxiliary source of information (e.g. Auto-Crop) now use small icons. Curve type icons are also small even though they have no labels.
- Colored circles are smaller.
- Curve type icons redesigned and small.
- Hand icons (when panning the preview) redesigned to have a clear outline regardless of background color.
- Magnifier icons redesigned to have a thinner magnifier frame and larger inner parts.
- Perspective, distortion and crop icons redesigned.
- Some small icons were missing the `-small` suffix, now renamed.

rtgui/toolpanel.cc

@@ -56,7 +56,7 @@ FoldableToolPanel::FoldableToolPanel(Gtk::Box* content, Glib::ustring toolName,
         label->set_alignment(Gtk::ALIGN_START, Gtk::ALIGN_CENTER);
         titleHBox->pack_start(*label, Gtk::PACK_EXPAND_WIDGET, 0);
 
-        RTImage *image = Gtk::manage (new RTImage("one-to-one.png"));
+        RTImage *image = Gtk::manage (new RTImage("one-to-one-small.png"));
         image->set_tooltip_text(M("TP_GENERAL_11SCALE_TOOLTIP"));
         titleHBox->pack_end(*image, Gtk::PACK_SHRINK, 0);