Update README.md

Update the download page link from the deleted wiki page to release page.
Update Windows Azure to Microsoft Azure
Microsoft Azure Pack is actually still called Windows Azure Pack, even though Windows Azure is now Microsoft Azure
Update windowsazure.com to azure.microsoft.com
Merge pull request #2460 from andrerod/master

Microsoft Azure Pack is still called Windows Azure Pack
Adding the Set-AzureVnetGatewayKey cmdlet

This commit adds the Set-AzureVnetGatewayKey cmdlet, as well as importing the latest nuget Network Management Library.
Merge pull request #1 from daschult/master

Adding the Set-AzureVnetGatewayKey cmdlet
Merge pull request #2 from Azure/dev

Pulling latest changes from Azure:dev to brooklyngwdev:dev
Merge branch 'dev' of https://github.com/brooklyngwdev/azure-sdk-tools into dev

Conflicts:
	WindowsAzurePowershell/src/Commands.ServiceManagement.Preview/packages.config
	WindowsAzurePowershell/src/Commands.ServiceManagement/packages.config
Merge branch 'dev' of https://github.com/Azure/azure-sdk-tools into dev
Merge branch 'master' of https://github.com/Azure/azure-sdk-tools into dev
Merge pull request #3 from brooklyngwdev/dev

Dev
Merge branch 'dev' of https://github.com/WindowsAzure/azure-sdk-tools into brooklyngwdev_master

Conflicts:
	WindowsAzurePowershell/src/Commands.ServiceManagement.Preview/Commands.ServiceManagement.Preview.csproj
	WindowsAzurePowershell/src/Commands.ServiceManagement.Preview/packages.config
	WindowsAzurePowershell/src/Commands.ServiceManagement/Commands.ServiceManagement.csproj
	WindowsAzurePowershell/src/Commands.ServiceManagement/packages.config
	WindowsAzurePowershell/src/Commands.Utilities/Commands.Utilities.csproj
	WindowsAzurePowershell/src/Commands.Utilities/packages.config
	WindowsAzurePowershell/src/Commands/Commands.csproj
	WindowsAzurePowershell/src/Commands/packages.config
Addressed code review comments
Merge pull request #2503 from stankovski/brooklyngwdev_master

Adding Set-AzureVnetGatewayKey cmdlet