Actually use intltool to merge in the AppData translations

Doing the .xml.in->.xml in configure works for paths, but not translations.
Fixed warning in recent_add() and recent_remove() when path is not absolute
by prepending g_get_current_dir() to it.
Report parsing error when loading a project.
Fixes Bug 712289 "Glade silently fails to open malformed ui file"
Sort object dependancy before saving using a topological
sorting algorithm _glade_tsort() instead of g_list_sort() with
glade_widget_depends() which is not a transitive property.

Closes Bug 709609 "[PATCH] Change way of sorting before writing XML output."
Fixes Bug 711858 "editing glade project results in long CPU usage spikes after upgrading to 3.16 and GTK+3.10"
Added toplevel-order test
Updated POTFILES.skip
Fixed bug in GtkScrolledWindow editor, vertical adjustmet was refering to the wrong property.
Remove timestamp from glade comment to avoid unnecessary changes in the file.
Fixes Bug 711863 'Remove "Generated with glade" XML comment'
Fixed <requires> tag output
GLADE_GTKBUILDER_HAS_VERSIONING check was broken for gtk >= 3.0
Fixed GtkBox virtual size property value on load.
This bug was introduced by commit 787cc5cac5d1950ac57783478279a9135c640995 which
fixed Bug 652655 "Setting entry on combobox moves the widget"
Fixed cellrenderer model column combobox chooser.
If treeview model is a filter or a sort model we need to walk up until
we find a tree or list store which is where glade have defined the model columns.
Fix issue with numeric property editors.
We have to make sure  glade_eprop_numeric_load() is not called during
glade_eprop_numeric_force_update() to prevent gtk_spin_button_set_value()
changing the the value the user is trying to input.
Fixed identation spaces in function declarations.