Pressing Esc in resource overview bar crashes

[ChrisOelmueller]

• Load game
• Hover resource overview bar
• Hit Esc

Traceback (most recent call last):
  File "/home/eoc/UH/unknown-horizons/horizons/gui/keylisteners/ingamekeylistener.py", line 68, in keyPressed
    if self.session.ingame_gui.on_key_press(action, evt):
  File "/home/eoc/UH/unknown-horizons/horizons/gui/ingamegui.py", line 389, in on_key_press
    return self.on_escape()
  File "/home/eoc/UH/unknown-horizons/horizons/gui/ingamegui.py", line 344, in on_escape
    self.cursor.on_escape()
  File "/home/eoc/UH/fife/engine/python/fife/fife.py", line 2851, in <lambda>
    __getattr__ = lambda self, name: _swig_getattr(self, IMouseListener, name)
  File "/home/eoc/UH/fife/engine/python/fife/fife.py", line 55, in _swig_getattr
    raise AttributeError(name)
AttributeError: on_escape

[totycro]

This is related to 3fb4239

The problem is that there are cursor tools, which are not SelectionTool, but still don't have an on_escape, in this case ResBarMouseTool.

How about using hasattr? Then all cursor tools, that have a meaningful action on escape could get it, all other, such as SelectionTool, would not.