Added explicit virtualenv versioning
Remove the invewrapper name from the README
Check for PATH problems before dropping the user into a shell
Error handling: since we already got the stdout and stderr from subprocesses, lets suppress the exception
Also: delete the newly created virtualenv if its creation failed
For the prevent_path_errors to work correctly, we need to use the external python version that actually has pew installed
Removed all references to the old "invewrapper" name
Merge branch 'pew-rename'

Conflicts:
	pew/pew.py
Update readme troubleshooting