Python 3.3 Venv experiments

1. Custom env builder

• auto install distribute
• auto install pip
• install requirements (pip)
• upgrade venv and requirements
• python3.3 setup_venv.py

2. Test scripts.

• <venv>/bin/test_exec_env.py (. bin/activate required)
• <venv>/bin/python3 <venv>/bin/test_venv.py (. bin/activate not required)
• <venv>/bin/test_exec_fullpath.py (. bin/activate not required)