Complete GTK+ 3.5 fixes

usr/share/themes/Lubuntu-default/gtk-3.0/gtk-widgets-backdrop.css

@@ -958,7 +958,8 @@ GtkTextView:backdrop {
     color: shade (#a39e9a, 0.86); /* metacity unfocused color */
     text-shadow: 0 1px shade (@dark_bg_color, 1.06);
 
-    transition: 0ms ease-in-out;
+    /* This breaks Gtk+ 3.5.x, lp #1015497. */
+    /* transition: 0ms ease-in-out; */
 
     -unico-focus-border-radius: 4;
     -unico-focus-border-color: alpha (@backdrop_selected_bg_color, 0.5);
@@ -982,7 +983,8 @@ GtkTextView:backdrop {
 .primary-toolbar .button:insensitive:backdrop {
     border-width: 1px;
 
-    transition: 0ms ease-in-out;
+    /* This breaks Gtk+ 3.5.x, lp #1015497. */
+    /* transition: 0ms ease-in-out; */
 
     -unico-focus-border-radius: 0;
     -unico-focus-fill-color: @transparent;

usr/share/themes/Lubuntu-default/gtk-3.0/gtk-widgets.css

@@ -224,7 +224,8 @@ GtkComboBox,
     color: @fg_color;
     text-shadow: 0 1px alpha (shade (@button_bg_color, 1.25), 0.4);
 
-    transition: 100ms ease-in-out;
+    /* This breaks Gtk+ 3.5.x, lp #1015497. */
+    /* transition: 100ms ease-in-out; */
 
     -unico-border-gradient: -gtk-gradient (linear, left top, left bottom,
                                            from (shade (@button_bg_color, 0.85)),
@@ -1793,7 +1794,8 @@ GtkTextView {
     color: @dark_fg_color;
     text-shadow: 0 1px alpha (shade (@dark_bg_color, 1.25), 0.32);
 
-    transition: 0ms ease-in-out;
+    /* This breaks Gtk+ 3.5.x, lp #1015497. */
+    /* transition: 0ms ease-in-out; */
 
     -unico-focus-border-radius: 4;
     -unico-focus-border-color: alpha (@selected_bg_color, 0.5);
@@ -1813,7 +1815,8 @@ GtkTextView {
 .primary-toolbar .button:insensitive {
     border-width: 1px;
 
-    transition: 0ms ease-in-out;
+    /* This breaks Gtk+ 3.5.x, lp #1015497. */
+    /* transition: 0ms ease-in-out; */
 
     -unico-inner-stroke-width: 1px;
     -unico-outer-stroke-gradient: -gtk-gradient (linear, left top, left bottom,