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/icmpanel.cc

@@ -139,7 +139,7 @@ ICMPanel::ICMPanel () : FoldableToolPanel(this, "icm", M("TP_ICM_LABEL")), iunch
     iVBox->pack_start (*dcpFrame);
 
     saveRef = Gtk::manage (new Gtk::Button (M("TP_ICM_SAVEREFERENCE")));
-    saveRef->set_image (*Gtk::manage (new RTImage ("save.png")));
+    saveRef->set_image (*Gtk::manage (new RTImage ("save-small.png")));
     saveRef->set_alignment (0.5f, 0.5f);
     saveRef->set_tooltip_markup (M("TP_ICM_SAVEREFERENCE_TOOLTIP"));
     iVBox->pack_start (*saveRef, Gtk::PACK_SHRINK);