add fullscreen support for QtConsole throught shortcut

	add a toggleFullscreen action to qtconsoleapp and connect it to the
	'Ctrl+Meta+Space' shortcut (which is Command+Ctrl+Space on Mac)
	add shortcut description in %guiref

move maximize and minimize shortcut/fonction to another branch

IPython/core/usage.py

@@ -416,6 +416,7 @@
 - ``C-.``: force a kernel restart (a confirmation dialog appears).
 - ``C-+``: increase font size.
 - ``C--``: decrease font size.
+- ``C-M-Space``: toggle full screen. (Command-Control-Space on Mac OS X)
 
 The IPython pager
 =================

IPython/frontend/qt/console/qtconsoleapp.py

@@ -98,7 +98,7 @@ def __init__(self, app, frontend, existing=False, may_close=True,
         self._frontend.exit_requested.connect(self.close)
         self._confirm_exit = confirm_exit
         self.setCentralWidget(frontend)
-    
+
     #---------------------------------------------------------------------------
     # QWidget interface
     #---------------------------------------------------------------------------
@@ -461,6 +461,19 @@ def initialize(self, argv=None):
         self.init_kernel_manager()
         self.init_qt_elements()
         self.init_colors()
+        self.init_window_shortcut()
+
+    def init_window_shortcut(self):
+        fullScreenAction = QtGui.QAction('Toggle Full Screen', self.window)
+        fullScreenAction.setShortcut('Ctrl+Meta+Space')
+        fullScreenAction.triggered.connect(self.toggleFullScreen)
+        self.window.addAction(fullScreenAction)
+
+    def toggleFullScreen(self):
+        if not self.window.isFullScreen():
+            self.window.showFullScreen()
+        else:
+            self.window.showNormal()
 
     def start(self):