* windows_feature resource: Add DISM support
This modifies the `windows_feature` resource to fallback to DISM when
the `Get-WindowsFeature` command is not available.
* Allow specifying `:dism` or `:powershell`
* Replace stacktrace with smaller error message
* Add notes/todo about raise behavior
* Remove duplicated platform check
Signed-off-by: Jerry Aldrich <jerryaldrichiii@gmail.com>
