If you ever want to install OpenStack using packstack from the master branch (Git repository), follow these steps:

$ git clone --recursive git://github.com/stackforge/packstack.git
$ cd packstack
$ ./bin/packstack --allinone --os-neutron-install=y --provision-demo=n --provision-all-in-one-ovs-bridge=n

Those commands will clone and fetch the latest snapshot of packstack from its Git repository. Then, will invoke packstack to install OpenStack, enabling Neutron (networking) and disabling the provisioning of the demo tenant (and related network configuration). The command-line flags provided to packstack are intended for running OpenStack in a single machine.