Called when a key is released when the command entry box has focus.

def onKeyReleaseInCanvas(self, event):
        '''Called when a key is released when the command entry box has focus.'''
        char_map = { 'w':'move 0', 'a':'strafe 0', 's':'move 0', 'd':'strafe 0', ' ':'jump 0' }
        keysym_map = { 'Left':'turn 0', 'Right':'turn 0', 'Up':'pitch 0', 'Down':'pitch 0', 'Shift_L':'crouch 0', 'Shift_R':'crouch 0', 
                       '1':'hotbar.1 0', '2':'hotbar.2 0', '3':'hotbar.3 0', '4':'hotbar.4 0', '5':'hotbar.5 0',
                       '6':'hotbar.6 0', '7':'hotbar.7 0', '8':'hotbar.8 0', '9':'hotbar.9 0' }
        if event.char.lower() in char_map:
            self.agent_host.sendCommand( char_map[ event.char.lower() ] )
        elif event.keysym in keysym_map:
            self.agent_host.sendCommand( keysym_map[ event.keysym ] )