Add support for backups with vvv-site-wizard

These changes create an additional database backup and place it within the site directory for projects generated by the `vvv-site-wizard` script by Alison Barrett https://github.com/aliso/vvv-site-wizard

If the default directory is not found, a warning "error" is thrown and the script continues. 

I have also included a fix to add backups to the default VVV WordPress installs. Users can uncomment line 26 to enable those extra backups. Since the default installs are intended for theme/plugin testing, they should not have important information. However the option is there. If users do not uncomment line 26, the "error" described above is thrown and the script continues.

All databases are still saved in the normal /database/backups/ directory.

I also cleaned up the output formatting and added some color highlighting to show success/errors.