docs: Remove '\' escape character from literals

commit 7f6a964c47 replaced entities, but
escaped the replacement text also inside literals, which resulted in the
escaping '\' to also appear in the documentation.

https://bugzilla.gnome.org/show_bug.cgi?id=727322

gdk/gdkcolor.c

@@ -163,7 +163,7 @@ gdk_color_parse (const gchar *spec,
  * @color: a #GdkColor
  *
  * Returns a textual specification of @color in the hexadecimal
- * form `\#rrrrggggbbbb`, where `r`, `g` and `b` are hex digits
+ * form `#rrrrggggbbbb`, where `r`, `g` and `b` are hex digits
  * representing the red, green and blue components respectively.
  *
  * The returned string can be parsed by gdk_color_parse().

gtk/gtkaboutdialog.c

@@ -79,7 +79,7 @@
  * use the function gtk_show_about_dialog() which constructs and shows a dialog
  * and keeps it around so that it can be shown again.
  *
- * Note that GTK+ sets a default title of `_("About \%s")` on the dialog
+ * Note that GTK+ sets a default title of `_("About %s")` on the dialog
  * window (where \%s is replaced by the name of the application, but in
  * order to ensure proper translation of the title, applications should
  * set the title property explicitly when constructing a GtkAboutDialog,

gtk/gtkcssprovider.c

@@ -103,7 +103,7 @@
  * various ways:
  * - To require that a widget satisfies several conditions,
  *   combine several selectors into one by concatenating them. E.g.
- *   `GtkButton\#button1` matches a GtkButton widget
+ *   `GtkButton#button1` matches a GtkButton widget
  *   with the name button1.
  * - To only match a widget when it occurs inside some other
  *   widget, write the two selectors after each other, separated by whitespace.

gtk/gtksettings.c

@@ -979,8 +979,8 @@ gtk_settings_class_init (GtkSettingsClass *class)
    * GtkSettings:gtk-print-preview-command:
    *
    * A command to run for displaying the print preview. The command
-   * should contain a `\%f` placeholder, which will get replaced by
-   * the path to the pdf file. The command may also contain a `\%s`
+   * should contain a `%f` placeholder, which will get replaced by
+   * the path to the pdf file. The command may also contain a `%s`
    * placeholder, which will get replaced by the path to a file
    * containing the print settings in the format produced by
    * gtk_print_settings_to_file().

gtk/gtkshow.c

@@ -39,7 +39,7 @@
  * Typical examples are
  * - `file:///home/gnome/pict.jpg`
  * - `http://www.gnome.org`
- * - `mailto:me\@gnome.org`
+ * - `mailto:me@gnome.org`
  * Ideally the timestamp is taken from the event triggering
  * the gtk_show_uri() call. If timestamp is not known you can take
  * %GDK_CURRENT_TIME.