Resaved everything with Glade 3.38 which changes all of the properties from

  using _'s to using -'s.
Make sure everything has the license information, including the menu files

  that Glade doesn't handle directly.
Make sure that all of our ui files are requiring Gtk 3.22 as that is our

  minimum and many of them were set to 3.20 which was making Glade angry.
Change the margin-left to margin-start in xfer.ui

Glade is doing some weird stuff though that we'll need to watch in the future.  Namely the format view isn't showing up as an internal client in TalkatuEditor for some reason and Glade removed the property from the Invisible GtkTextTag.

Compiled and ran locally.