Make the new calibre style default on windows and OS X

src/calibre/gui2/__init__.py

@@ -106,7 +106,7 @@ gprefs.defaults['auto_add_path'] = None
 gprefs.defaults['auto_add_check_for_duplicates'] = False
 gprefs.defaults['blocked_auto_formats'] = []
 gprefs.defaults['auto_add_auto_convert'] = True
-gprefs.defaults['widget_style'] = 'system'
+gprefs.defaults['ui_style'] = 'calibre' if iswindows or isosx else 'system'
 # }}}
 
 NONE = QVariant() #: Null value to return from the data function of item models
@@ -782,7 +782,7 @@ class Application(QApplication):
                 font.setStretch(s)
             QApplication.setFont(font)
 
-        if force_calibre_style or gprefs['widget_style'] != 'system':
+        if force_calibre_style or gprefs['ui_style'] != 'system':
             self.load_calibre_style()
         else:
             st = self.style()

src/calibre/gui2/preferences/look_feel.py

@@ -101,7 +101,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
         r('gui_layout', config, restart_required=True, choices=
                 [(_('Wide'), 'wide'), (_('Narrow'), 'narrow')])
-        r('widget_style', gprefs, restart_required=True, choices=
+        r('ui_style', gprefs, restart_required=True, choices=
                 [(_('System default'), 'system'), (_('Calibre style'),
                     'calibre')])
 

src/calibre/gui2/preferences/look_feel.ui

@@ -187,12 +187,12 @@
           <string>User interface &amp;style (needs restart):</string>
          </property>
          <property name="buddy">
-          <cstring>opt_widget_style</cstring>
+          <cstring>opt_ui_style</cstring>
          </property>
         </widget>
        </item>
        <item row="0" column="1">
-        <widget class="QComboBox" name="opt_widget_style"/>
+        <widget class="QComboBox" name="opt_ui_style"/>
        </item>
       </layout>
      </widget>