Remove IE-parity Backspace and Shift-Backspace bindings because they confuse unders. Bug 69981. r=jag, sr=blake.

suite/browser/win/platformNavigationBindings.xul

@@ -9,11 +9,6 @@
     <key id="goBackKb"  keycode="VK_LEFT" command="Browser:Back" modifiers="alt"/>
     <key id="goForwardKb"  keycode="VK_RIGHT" command="Browser:Forward" modifiers="alt"/>
 
-    <!-- Supporting IE forward and back accelerators out of courtesy
-         to transitioning IE users -->
-    <key keycode="VK_BACK" command="Browser:Back"/>
-    <key keycode="VK_BACK" command="Browser:Forward" modifiers="shift"/>
-
     <!-- Supporting IE 'refresh' shortcut key -->
     <key keycode="VK_F5" oncommand="BrowserReload();"/>
     <key keycode="VK_F5" modifiers="control" oncommand="BrowserReloadSkipCache();"/>