**Summary**:
* Adds doc section on troubleshooting Watchmaker, to include common errors, issues,
and relevant log files
* Updates AWS provider to support EC2 instances configured for only IMDSv2
* ash-linux-formula
- Addresses additional STIG findings for EL7 and EL8
* join-domain-formula
- Resolves issue with collision detection when deploying a new system
with a hostname that already exists in the domain
- Corrects usage of StartTLS when searching for a computer object in the
domain
- Provides several new options for controlling whether TLS is used when
searching for a computer object in the domain, and whether an error will
be treated as fatal or not