* Eliminate CleanPublishOutput
* Decompose Crossgen Task
* WiP
* TarGzFileExtractToDirectory
* FixModeFlags --> CHMod
Also various eliminations of dead code
* Tasks cleanup
Move all tasks to .tasks file. There is little value in keepint them in each source file as they are already being used assumptively by files that happen to get executed later.
Also eliminating uses of <Exec> for DotNet invocations
* Move to BuildTools implementation of TarGzCreateFromDirectory
* Eliminate Command.cs and helpers
* Remove dead code
* Revert TarGz from BuildTools
Latest build tools package has not picked up the task, though it is checked in.
* Disable ChMod on Windows
* Windows bug fix
* PR Feedback
* Finish changing Chmod caps
Ubuntu is currently broken because we added a new channel, and a switch statement wasn't expecting the new channel.
The fix is to eliminate the switch statement on the channel and always return "dotnet-dev-<version>" for the debian sdk package name.
