Update common to pull down the non-ppa python on 16.04

This prevented the -b option to install_stack.sh from working properly.

Now the install happens in the current directory, with logs in a 'logs'
subdirectory.

Other improvements: curl now fails if the Vagrantfile can't be
downloaded, because the RELEASE value is invalid.  Curl also doesn't
print as large a progress bar.  The script fails early if there's no
RELEASE specified.

(cherry picked from commit 66a25250)

Now the install happens in the current directory, with logs in a 'logs'
subdirectory.

Other improvements: curl now fails if the Vagrantfile can't be
downloaded, because the RELEASE value is invalid.  Curl also doesn't
print as large a progress bar.  The script fails early if there's no
RELEASE specified.

(cherry picked from commit a8bd50f9)

Install script will work with master and most-recent named-release (dogwood) versions only. Will not work with weekly releases, or previous named-releases.

Pip 8.0.0, released a few hours ago, tries to uninstall deb-installed
python modules that it wants to upgrade, and always fails when doing so.
The effect is that configuration/requirements.txt cannot be fulfilled,
notably ansible 1.9.3-edx, which requires an upgrade to pycrypto.

This forces the installation of pip to the latest one prior to 8.0.0,
7.1.2.

It also freezes setuptools and virtualenv, so that they should all match
the current versions required on
playbooks/roles/common_vars/defaults/main.yml:common_pip_pkgs.

Pip 8.0.0, released a few hours ago, tries to uninstall deb-installed
python modules that it wants to upgrade, and always fails when doing so.
The effect is that configuration/requirements.txt cannot be fulfilled,
notably ansible 1.9.3-edx, which requires an upgrade to pycrypto.

This forces the installation of pip to the latest one prior to 8.0.0,
7.1.2.

It also freezes setuptools and virtualenv, so that they should all match
the current versions required on
playbooks/roles/common_vars/defaults/main.yml:common_pip_pkgs.