Wrap virtualenv binary test in try/except
Wrap virtualenv binary test in try/except

As discussed with carljm check and rethrow.

python virtualenv.py /mnt/tmp/ve
New python executable in /mnt/tmp/ve/bin/python
ERROR: The executable /mnt/tmp/ve/bin/python could not be run: [Errno
13] Permission denied

francatore/virtualenv,RAS-ViVa/virtualenv,jedie/virtualenv,RAS-ViVa/virtualenv,msabramo/virtualenv,vvtam/virtualenv,ionelmc/virtualenv,mykemunson/virtualenv,haridsv/virtualenv,haridsv/virtualenv,kissthink/virtualenv,mykemunson/virtualenv,blueyed/virtualenv,bigplus/virtualenv,vvtam/virtualenv,dstufft/virtualenv,davidszotten/virtualenv,msabramo/virtualenv,bigplus/virtualenv,blueyed/virtualenv,dstufft/virtualenv,kissthink/virtualenv,davidszotten/virtualenv,Ivoz/virtualenv,Seha16/virtualenv,Ivoz/virtualenv,techtonik/virtualenv,Lyleo/virtualenv,jedie/virtualenv,ionelmc/virtualenv,francatore/virtualenv,Lyleo/virtualenv,msabramo/virtualenv,ionelmc/virtualenv,madprog/virtualenv,techtonik/virtualenv,madprog/virtualenv,Seha16/virtualenv