Update pre-install to manage database

Three scripts:

• install.sql create database schema
• uninstall.sql remove database schema
• update.sql modify existing database schema (not used yet)

During pre-install

• prompt whether to install/update schema
• prompt whether to create read/write user
• (if installing or updating, prompt for admin user, make changes)

During uninstall

• prompt whether to remove schema
• prompt whether to remove read/write user
• (if removing, prompt for admin user, make changes)