Move virtualenv installation out of the makefile.

Also adds some tools for dealing with virtualenvs to the tools
directory.

.bzrignore

@@ -1 +1,2 @@
 run_tests.err.log
+.nova-venv

.gitignore

@@ -9,3 +9,4 @@ keys
 build/*
 build-stamp
 nova.egg-info
+.nova-venv

Makefile

@@ -1,27 +1,27 @@
-venv=.venv
-with_venv=source $(venv)/bin/activate
-installed=$(venv)/lib/python2.6/site-packages
-twisted=$(installed)/twisted/__init__.py
+venv=.nova-venv
+with_venv=tools/with_venv.sh
 
+build:
+	# Nothing to do
 
-test: python-dependencies $(twisted)
-	$(with_venv) && python run_tests.py
+test: $(venv)
+	$(with_venv) python run_tests.py
+
+test-system:
+	python run_tests.py
 
 clean:
 	rm -rf _trial_temp
 	rm -rf keys
 	rm -rf instances
 	rm -rf networks
+	rm run_tests.err.log
 
 clean-all: clean
 	rm -rf $(venv)
 
-python-dependencies: $(venv)
-	pip install -q -E $(venv) -r tools/pip-requires
-
 $(venv):
-	pip install -q virtualenv
-	virtualenv -q --no-site-packages $(venv)
-
-$(twisted):
-	pip install -q -E $(venv) http://nova.openstack.org/Twisted-10.0.0Nova.tar.gz
+	@echo "You need to install the Nova virtualenv before you can run this."
+	@echo ""
+	@echo "Please run tools/install_venv.py"
+	@exit 1