Don't hard-code database passwords

[annabunches]

Currently, building this program requires defining database information in db_passwords.h. This is:

1. Cumbersome. It requires recompiling for each environment, and if DB passwords, IPs, etc, change.
2. Insecure. It turns the compiled binaries into sensitive data, without necessarily making it obvious that they are sensitive data.
3. Difficult to containerize. Containers want all configuration to be via environment variables. (or at the very worst, config files)

This configuration should be replaced with environment variables.