[gnome-documents] utils: Add support for DjVu suffixes

[Bastien Nocera <hadess src gnome org>]

commit d720014df3d57af2b50225fa5f5ed9cdd7eefd80
Author: Bastien Nocera <hadess hadess net>
Date:   Mon May 30 19:00:46 2016 +0200

    utils: Add support for DjVu suffixes
    
    In case that's needed in the future...
    
    https://bugzilla.gnome.org/show_bug.cgi?id=767035

 src/lib/gd-utils.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/src/lib/gd-utils.c b/src/lib/gd-utils.c
index 0ed952d..6f841ef 100644
--- a/src/lib/gd-utils.c
+++ b/src/lib/gd-utils.c
@@ -185,6 +185,10 @@ gd_filename_to_mime_type (const gchar *filename_with_extension)
 
   if (g_strcmp0 (extension, ".pdf") == 0)
     type = "application/pdf";
+  else if (g_strcmp0 (extension, ".djv") == 0)
+    type = "image/vnd.djvu+multipage";
+  else if (g_strcmp0 (extension, ".djvu") == 0)
+    type = "image/vnd.djvu+multipage";
   else if (g_strcmp0 (extension, ".epub") == 0)
     type = "application/epub+zip";
   else if (g_strcmp0 (extension, ".cbr") == 0)
@@ -235,6 +239,8 @@ gd_filename_to_rdf_type (const gchar *filename_with_extension)
     type = "nfo:PaginatedTextDocument";
 
   else if (g_strcmp0 (extension, ".epub") == 0
+           || g_strcmp0 (extension, ".djv") == 0
+           || g_strcmp0 (extension, ".djvu") == 0
            || g_strcmp0 (extension, ".cbr") == 0
            || g_strcmp0 (extension, ".cbz") == 0
            || g_strcmp0 (extension, ".cbt") == 0