* Remove controlling echoing by command
* Add 'echo on' and 'echo off' action commands
* PR feedback and add L0 tests
* Register new command
* Eric's PR feedback
* Tweak logging a bit
* Rename EchoOnActionCommandSuccess -> EchoOnActionCommand
* More PR reaction
* Make warning messages in Action Commands not rely on context from echo commands
* Don't retry uploads when the http status code
response from the server is in the 400's
* Don't retry on fast-fail
* Feedback from code review
* Always try to attach any uploaded files to the build
Don't fast-fail on 'Conflict'
* Add dispose
* Refactored upload code.
Called out specialized 'Conflict' logic.
* Added typed exception.
