Initial refactor

* main() passes arguments to devsite() and does basic checks and
  sets up variables.
* devsite() calls out to helper functions to perform most tasks.
Don't try to overwrite settings.php

Added @todo about potentially adding this back as an append later.
Create database based on first argument
Document first argument
Don't bother restoring CONFIG_PATH permissions
Write database settings to settings.local.php
Write basic drushrc.php