fixed #107 and added persistent configuration

dialogs/preferencesdialog.cpp

@@ -1,6 +1,8 @@
 #include "preferencesdialog.h"
 #include "ui_preferencesdialog.h"
 
+#include "io/config.h"
+
 #include <QMenuBar>
 #include <QAction>
 #include <QDebug>
@@ -20,6 +22,8 @@ PreferencesDialog::PreferencesDialog(QWidget *parent) :
     ui(new Ui::PreferencesDialog)
 {
     ui->setupUi(this);
+
+    ui->imgSeqFormatEdit->setText(config.img_seq_formats);
 }
 
 PreferencesDialog::~PreferencesDialog() {
@@ -69,3 +73,7 @@ void PreferencesDialog::setup_kbd_shortcuts(QMenuBar* menubar) {
         }
     }
 }
+
+void PreferencesDialog::on_buttonBox_accepted() {
+    config.img_seq_formats = ui->imgSeqFormatEdit->text();
+}

dialogs/preferencesdialog.h

@@ -19,6 +19,9 @@ public:
 
     void setup_kbd_shortcuts(QMenuBar* menu);
 
+private slots:
+    void on_buttonBox_accepted();
+
 private:
     Ui::PreferencesDialog *ui;
 };

dialogs/preferencesdialog.ui

@@ -17,12 +17,24 @@
    <item>
     <widget class="QTabWidget" name="tabWidget">
      <property name="currentIndex">
-      <number>2</number>
+      <number>0</number>
      </property>
      <widget class="QWidget" name="tab">
       <attribute name="title">
        <string>General</string>
       </attribute>
+      <layout class="QGridLayout" name="gridLayout_2">
+       <item row="0" column="0">
+        <widget class="QLabel" name="label">
+         <property name="text">
+          <string>Image sequence formats:</string>
+         </property>
+        </widget>
+       </item>
+       <item row="0" column="1">
+        <widget class="QLineEdit" name="imgSeqFormatEdit"/>
+       </item>
+      </layout>
      </widget>
      <widget class="QWidget" name="tab_2">
       <attribute name="title">