Remove optional parameter ExtensionId
Merge branch 'dev' of git://github.com/AzureRT/azure-sdk-tools into dev

Conflicts:
	WindowsAzurePowershell/src/Management.ServiceManagement/Extensions/SetAzureServiceRemoteDesktopExtension.cs
Merge branch 'dev' of git://github.com/AzureRT/azure-sdk-tools into dev
Merge branch 'dev' of git://github.com/AzureRT/azure-sdk-tools into dev
Merge branch 'dev' of git://github.com/WindowsAzure/azure-sdk-tools into dev
New Cmdlets: Set-AzureServiceRemoteDesktop, Remove-AzureServiceRemoteDesktop, Get-AzureServiceRemoteDesktop
New Cmdlets: Set-AzureServiceRemoteDesktopExtension, Remove-AzureServiceRemoteDesktopExtension, Get-AzureServiceRemoteDesktopExtension, New-AzureServiceRemoteDesktopExtension
Merge branch 'dev' of https://github.com/huangpf/azure-sdk-tools into dev

Conflicts:
	WindowsAzurePowershell/src/Management.ServiceManagement/Extensions/SetAzureServiceRemoteDesktopExtension.cs
	WindowsAzurePowershell/src/Management.ServiceManagement/Management.ServiceManagement.csproj
Merge branch 'dev' of https://github.com/huangpf/azure-sdk-tools into dev

Conflicts:
	WindowsAzurePowershell/src/Management.ServiceManagement/Extensions/SetAzureServiceRemoteDesktopExtension.cs
	WindowsAzurePowershell/src/Management.ServiceManagement/Management.ServiceManagement.csproj
Merge branch 'dev' of https://github.com/huangpf/azure-sdk-tools into dev
Bug fix.
Re-using thumbprints from the to-be-deleted extension.
New-AzureServiceRemoteDesktopExtensionConfig
Re-using Thumbprints from Existing Extensions
Add Diagnostics Cmdlets
HostedServiceExtensionManager
Using Linq and Xml for parsing and config string construction.
Refactor codes using Linq and Xml to address code review. Use ExtensionManager to handle major tasks including check/add/remove extension and role in configuration, and delete/install hosted extensions.
Add ExtensionConfigurationBuilder to manage add/remove/check all-role or named-role extension in the configuration. Plus a few other refactoring and fixes.
Design:
- Move CheckExtensionType() to ExtensionManager
- Renaming Thumbprint to CertificateThumbprint
- Removing ServiceName from New- cmdlets

Re: Review:
- Remove ConvertToSecureString() and use namespace
- Refactor Get- cmdlets' Linq queries
- Redundant code in ExtensionRole

Apply fixes:
- Should not upload certificate in the new- cmdlets
- Config builder in New-/Set- Deployment should continue to add new config context