Fixed for wxPython 2.9.4.0 on Mac.

I was getting this:

Traceback (most recent call last):
  File "/users/pmcnett/dabo/dabo/ui/uiwx/dPemMixin.py", line 733, in __onWxResize
    self.raiseEvent(dEvents.Resize, evt)
  File "/users/pmcnett/dabo/dabo/ui/uiwx/dPemMixin.py", line 1074, in raiseEvent
    super(dPemMixin, self).raiseEvent(eventClass, nativeEvent, *args, **kwargs)
  File "/users/pmcnett/dabo/dabo/lib/eventMixin.py", line 81, in raiseEvent
    bindingFunction(event)
  File "/users/pmcnett/dabo/dabo/ui/uiwx/dImage.py", line 89, in _onResize
    self._showPic()
  File "/users/pmcnett/dabo/dabo/ui/uiwx/dImage.py", line 221, in _showPic
    img = img.Scale(imgW, imgH)
  File "/usr/local/lib/wxPython-2.9.4.0/lib/python2.7/site-packages/wx-2.9.4-osx_cocoa/wx/_core.py", line 2916, in Scale
    return _core_.Image_Scale(*args, **kwargs)
wx._core.PyAssertionError: C++ assertion "(width > 0) && (height > 0)" failed at /BUILD/wxPython-src-2.9.4.0/src/common/image.cpp(434) in Scale(): invalid new image size

self.Width and self.Height were 0,0 but the original test for an uninitialized
image was for w,h or 1,1.
Fix DeprecationWarning on wxPython 2.9

wx.InitAllImageHandlers() is done implicitly now by wxPython.
Fix _getID() to get it from wx.NewId().

Prior to this, we were filling dMenu id's using the logic from dObject,
which was to return the python id. This doesn't work in 64-bit Python
because wxPython (even 64-bit wxPython) doesn't recognize large ints
as ints, causing a StackOverflow exception.

This is better also since we really want wx to dole out the id's for
wxPython objects.
Merge branch 'working' of github.com:dabodev/dabo into working