Start rewriting Vagrantfile for Ubuntu 14.04 (#2327 and #2868)
vagrant: Install PostgreSQL
vagrant: Comments and minor fixes
virtualenv: Do not symlink, because shared folders may not support them
vagrant: Add scripts/vagrant-debian.sh for system prerequisites
vagrant: Run scripts/vagrant-setup.sh for basebox
vagrant: Simplify scripts/vagrant-setup.sh

Windows Git doesn't mess with newlines by default anymore, so remove
that warning. Modify `/etc/profile.d` with sudo, demystify PostreSQL
command line.
vagrant: Merge db init .sql scripts in to reset-db.sql

This makes reprovisioning idempotent.
vagrant: Create vagrant role for PostreSQL and use that to access DB
Fix #2950 - fake_data generates 0.00 transfers that break positive constraint
Remove stray comments from gratipay/version.py
Merge pull request #2948 from gratipay/vagranting

Rebuilding Vagrant box with newer Ubuntu (fixes #2327)