Rationalise dev env a bit.

Removed lr- from dev env functions. Same functions available with dev- prefix.

Moved puppetisation to sub-directory of the dev env. The init.pp file imports other pp files
as needed.

Postgres, Mongo are installed and configured using puppetlabs modules.

Some additional config is still done from dev env bash script but more is done in puppet files instead.
The rest can be moved to puppet in time.

Python virtualenvs now live in ~/.virtualenvs.

Nginx config for apps in apps directory, just sets up site-available and proxy config. Hosts config (/etc/hosts)
is now done in a separate script.

Python 3 is installed but for the moment virtualenvs are still created with Python 2.

Vagrant file defaults memory to 4 GB. Set environment variable 'VM_MEMORY' to something lower if you have 4 GB on your
host system.
Corrected readme for new env changes
update github org name for checkout
Made puppet structure more sensible on advice from george
Merge branch 'new-dev-env'