Add Enable-AzureWebsiteApplicationDiagnostic scenario tests
WindowsAzure#1535
Merge branch 'dev' of https://github.com/WindowsAzure/azure-sdk-tools into 1548

Conflicts:
	WindowsAzurePowershell/src/Management.ScenarioTest/WebsitesTests/WebsitesTests.cs
Merge pull request #1575 from ogail/1548

Add Enable-AzureWebsiteApplicationDiagnostic scenario tests