Initial commit for real hidpi support

Note: This commit has only been tested on MacOS

Changes:
- Icons now use the native hidpi support from Gtk (through Icon Theme)
- Icons are now directly generated from scalable file (i.e. SVG file)
- Widget sizes are scaled based on DPI and scale factor
- Font size is scaled based on DPI and scale factor

rtgui/main.cc

@@ -68,7 +68,6 @@ Glib::ustring argv2;
 bool simpleEditor = false;
 bool gimpPlugin = false;
 bool remote = false;
-unsigned char initialGdkScale = 1;
 //Glib::Threads::Thread* mainThread;
 
 namespace
@@ -250,7 +249,7 @@ void cleanup_rt()
 
 RTWindow *create_rt_window()
 {
-    Glib::ustring icon_path = Glib::build_filename (argv0, "images");
+    Glib::ustring icon_path = Glib::build_filename (argv0, "icons");
     Glib::RefPtr<Gtk::IconTheme> defaultIconTheme = Gtk::IconTheme::get_default();
     defaultIconTheme->append_search_path (icon_path);
 
@@ -533,16 +532,6 @@ int main (int argc, char **argv)
 
     int ret = 0;
 
-    if (options.pseudoHiDPISupport) {
-        // Reading/updating GDK_SCALE early if it exists
-        const gchar *gscale = g_getenv("GDK_SCALE");
-        if (gscale && gscale[0] == '2') {
-            initialGdkScale = 2;
-        }
-        // HOMBRE: On Windows, if resolution is set to 200%, Gtk internal variables are SCALE=2 and DPI=96
-        g_setenv("GDK_SCALE", "1", true);
-    }
-
     gdk_threads_set_lock_functions (G_CALLBACK (myGdkLockEnter), (G_CALLBACK (myGdkLockLeave)));
     gdk_threads_init();
     gtk_init (&argc, &argv);  // use the "--g-fatal-warnings" command line flag to make warnings fatal