Crash in PyQt when launching the FileEditor's dialog from a TableEditor on OSX 10.11

I'm getting a crash in PyQt4 when I use a FileEditor in an ObjectColumn in a TableEditor. The OSX file picker flashes briefly, and then python.exe crashes.

It only seems to happen in OSX 10.11; 10.7, 10.8 and 10.10 work fine.

The following code reproduces the problem:

```
from traits.api import File, Str, HasTraits, List
from traitsui.api import View, Item, TableEditor, ObjectColumn

class _Control(HasTraits):
channel = Str
file = File

class Controls(HasTraits):

controls = List(_Control)

def default_traits_view(self):
return View(Item('controls',
editor=TableEditor(
columns =
[ObjectColumn(name = 'channel'),
ObjectColumn(name = 'file')])))

c = Controls(controls = [_Control()])
c.configure_traits()
```

When I use faulthandler to give me a backtrace, I get the following:

Fatal Python error: Segmentation fault

Current thread 0x00007fff76a24000 (most recent call first):
File "/Users/Allen/anaconda2/lib/python2.7/site-packages/traitsui/qt4/file_editor.py", line 127 in show_file_dialog
File "/Users/Allen/anaconda2/lib/python2.7/site-packages/pyface/util/guisupport.py", line 137 in start_event_loop_qt4
File "/Users/Allen/anaconda2/lib/python2.7/site-packages/traitsui/qt4/view_application.py", line 136 in **init**
File "/Users/Allen/anaconda2/lib/python2.7/site-packages/traitsui/qt4/view_application.py", line 83 in view_application
File "/Users/Allen/anaconda2/lib/python2.7/site-packages/traitsui/qt4/toolkit.py", line 212 in view_application
File "/Users/Allen/anaconda2/lib/python2.7/site-packages/traits/has_traits.py", line 2386 in configure_traits
File "test.py", line 24 in
Segmentation fault: 11

Launching the QFileDialog from other contexts seems to work: ie, in the above example, if I say `_Control().configure_traits()` and launch the file picker things work fine.

Relevant versions:
Python 2.7.12 (Anaconda x86_64)
traits 4.5.0
traitsui and pyface 5.1.0
pyqt4 4.11.4
Qt4 4.8.7