* Allow -validate flag to validate caddyfile and return

* Ensure logging without -log flag

* Changes to validate seperatly to Starup func

* Removed change to Start signature.  Created function to ValidateCaddyfile

* comment and tidyup

* ValidateandExecuteDirectives with justValidate option

* remove debugging code

* Tidy up comments

* additional parameter added to calls to mustLogFataf

* ValidateAndExecuteDirectives needs to only return err