Support Scheduled tasks for W2K8R2, W2K12, W2K12R2, W2K16

[otabut]

Instead of using SCHTASKS.EXE or ScheduledTasks Powershell module that are not fully supported on all OS versions, use of Schedule.Service COM object

[otabut]

Known issue with W2K8R2 only (still under investigation) :

• occurs only with Pester : service auto-starts after registration even without order or trigger
• service must be stopped after registration, otherwise Pester validation scripts will fail