Fix font errors and spacing in GTK 3.20+

Author: thebaer

src/window.vala

@@ -190,7 +190,7 @@ public class WriteAs.MainWindow : Gtk.ApplicationWindow {
         var styles = option.get_style_context();
         var provider = new Gtk.CssProvider();
         try {
-            provider.load_from_data("* {font: %s;}".printf(families));
+            provider.load_from_data("* {font-family: %s;}".printf(families));
             styles.add_provider(provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION);
         } catch (Error e) {
             warning(e.message);
@@ -230,7 +230,7 @@ public class WriteAs.MainWindow : Gtk.ApplicationWindow {
                 Gtk.StyleContext.remove_provider_for_screen(Gdk.Screen.get_default(), cur_styles);
 
             var padding = canvas.get_allocated_width()*0.10;
-            var css = ("GtkTextView {font: %s; font-size: %dpx; padding: 20px;" +
+            var css = ("textview {font-family: %s; font-size: %dpx; padding: 20px;" +
                     " padding-left: %ipx; padding-right: %ipx;" +
                     " -GtkWidget-cursor-color: #5ac4ee;}").printf(font, font_size,
                         (int) padding, (int) padding);