--User changes

-Attempt to preserve xaos when adding xforms. Note this is not an exact copy, but just a preservation of some values based on position.
 -Add some acceleration to the changing of spinner values when dragging the right mouse button to adjust.
 -Make the pivot be the center of the viewable area when doing drag/rotate/scale with the right mouse button.
 --Clamp minimum scale to 10
 --Draw a line from the mouse position to the pivot.
 -Keep a cache of the last added final xform with each flame so that it can be quickly added, removed, then added back for testing its effect.
 --This is not saved with the xml file and is solely for interactive editing.

--Bug fixes
 -File filtering in open and save dialogs were broken.
 -Right clicking on integer spin boxes was causing the context menu to pop up, when it should be supressed just like double spin boxes.
 -Deleting xforms was still broken.

--Code changes
 -Refactor the code for adding and pasting xforms into a single global static function called AddXformsWithXaos().

Source/Fractorium/Fractorium.ui

@@ -1922,10 +1922,13 @@
           </widget>
          </item>
          <item row="0" column="1">
-          <widget class="SpinBox" name="AddLayerSpinBox">
+          <widget class="QSpinBox" name="AddLayerSpinBox">
            <property name="focusPolicy">
             <enum>Qt::StrongFocus</enum>
            </property>
+           <property name="buttonSymbols">
+            <enum>QAbstractSpinBox::NoButtons</enum>
+           </property>
            <property name="suffix">
             <string> Xforms</string>
            </property>
@@ -8374,11 +8377,6 @@
    <extends>QTreeWidget</extends>
    <header>LibraryTreeWidget.h</header>
   </customwidget>
-  <customwidget>
-   <class>SpinBox</class>
-   <extends>QSpinBox</extends>
-   <header>spinbox.h</header>
-  </customwidget>
  </customwidgets>
  <tabstops>
   <tabstop>LibraryDockWidget</tabstop>