drop gtk2 support

Makefile

@@ -1,12 +1,6 @@
 PREFIX = /usr/local
-
-ifeq (${GTK3}, 1)
-	GTK = gtk+-3.0
-	VTE = vte-2.90
-else
-	GTK = gtk+-2.0
-	VTE = vte
-endif
+GTK = gtk+-3.0
+VTE = vte-2.90
 
 CFLAGS += -std=c99 -O3 \
 	  -Wall -Wextra -pedantic \

README.rst

@@ -5,7 +5,7 @@ Configuration is done at compile-time via ``config.h``.
 DEPENDENCIES
 ============
 
-A vte version >= 0.28. You can use vte3 by building with ``make GTK3=1``.
+A vte version >= 0.30.
 
 KEYBINDINGS
 ===========

termite.c

@@ -262,20 +262,11 @@ int main(int argc, char **argv) {
 
 #ifdef TRANSPARENCY
     GdkScreen *screen = gtk_widget_get_screen(window);
-
-#if GTK_CHECK_VERSION(2, 90, 7)
     GdkVisual *visual = gdk_screen_get_rgba_visual(screen);
     if (!visual) {
         visual = gdk_screen_get_system_visual(screen);
     }
     gtk_widget_set_visual(GTK_WIDGET(window), visual);
-#else
-    GdkColormap *colormap = gdk_screen_get_rgba_colormap(screen);
-    if (colormap) {
-        gtk_widget_set_colormap(window, colormap);
-    }
-#endif
-
     vte_terminal_set_background_saturation(VTE_TERMINAL(vte), TRANSPARENCY);
     vte_terminal_set_opacity(VTE_TERMINAL(vte), (guint16)(0xffff * (1 - TRANSPARENCY)));
 #endif