First iteration of a Dockerfile for the Drupal test bot

This was done for CentOS, because I couldn't get it working for the Debian image.  I'll
keep working on this to make it work for Debian instead
Update to be run on Debian, and consistent with the MySQL image
Initial support for startup.sh script in Dockerfile
Adjust the way we start PostgreSQL in the startup.sh file
Add build.sh, based on the MySQL version
Fix a mysql-ism in the startup.sh script, and check in more shell scripts
Fix things so that PostgreSQL actually starts up as expected
Run without tmpfs for now... we'll fix it later
Fix up the host-based authentication and listening IP address
Create database users with SQL commands
Merge pull request #9 from jaredsmith/master

First iteration of a PostgreSQL Dockerfile for the Drupal test bot