remove GtkQSortFilterTreeModel

This Qt model wrapper class was added because GtkQTreeModel didn't
seem to work for QSortFilterProxy models; however this does not seem
to be the case any longer. Either something was fixed in the
GtkQTreeModel code, or else the initial problem was due to another
bug. Either way this reduces and simplifies the code base.

Change-Id: I8d1f7bb83c17708e2ef3c544ee32c13a4b2b3e7d
diff --git a/src/accountview.cpp b/src/accountview.cpp
index 30ef947..9ba34f1 100644
--- a/src/accountview.cpp
+++ b/src/accountview.cpp
@@ -26,7 +26,7 @@
 #include <protocolmodel.h>
 #include <QtCore/QItemSelectionModel>
 #include "models/gtkqtreemodel.h"
-#include "models/gtkqsortfiltertreemodel.h"
+#include "models/gtkqtreemodel.h"
 #include "models/activeitemproxymodel.h"
 #include "accountgeneraltab.h"
 #include "accountaudiotab.h"
@@ -305,8 +305,8 @@
     if (gtk_combo_box_get_active_iter(GTK_COMBO_BOX(priv->combobox_account_type), &protocol_iter)) {
         /* get the qmodelindex of the protocol */
         GtkTreeModel *protocol_model = gtk_combo_box_get_model(GTK_COMBO_BOX(priv->combobox_account_type));
-        QModelIndex protocol_idx = gtk_q_sort_filter_tree_model_get_source_idx(
-                                    GTK_Q_SORT_FILTER_TREE_MODEL(protocol_model),
+        QModelIndex protocol_idx = gtk_q_tree_model_get_source_idx(
+                                    GTK_Q_TREE_MODEL(protocol_model),
                                     &protocol_iter);
         if (protocol_idx.isValid()) {
             protocol_idx = priv->active_protocols->mapToSource(protocol_idx);
@@ -504,7 +504,7 @@
     /* TODO: when to delete this model? */
     priv->active_protocols = new ActiveItemProxyModel((QAbstractItemModel *)AccountModel::instance().protocolModel());
 
-    GtkQSortFilterTreeModel *protocol_model = gtk_q_sort_filter_tree_model_new(
+    GtkQTreeModel *protocol_model = gtk_q_tree_model_new(
                                                 (QSortFilterProxyModel *)priv->active_protocols,
                                                 1,
                                                 0, Qt::DisplayRole, G_TYPE_STRING);
@@ -544,8 +544,8 @@
     if (protocol_idx.isValid()) {
         protocol_idx = priv->active_protocols->mapFromSource(protocol_idx);
         GtkTreeIter protocol_iter;
-        if (gtk_q_sort_filter_tree_model_source_index_to_iter(
-                (GtkQSortFilterTreeModel *)protocol_model,
+        if (gtk_q_tree_model_source_index_to_iter(
+                (GtkQTreeModel *)protocol_model,
                 protocol_idx,
                 &protocol_iter)) {
             gtk_combo_box_set_active_iter(GTK_COMBO_BOX(priv->combobox_account_type), &protocol_iter);