Update sql-database-auditing-get-started.md

Removing preview text - Azure SQL DB Auditing became GA
Merged with master
fix azure sendgrid php documentation
fix azure sendgrid php documentation
fix azure sendgrid php documentation
Changed documentation for nodeJs
sendgrid-java
sendgrid node js
updated "Send email from Mobile Services with SendGrid"
update "Send email from Mobile Services with SendGrid"
sendgrid mobile
update "Send email from Mobile Services with SendGrid"
sendgrid mobile
minor fixes
Adding images for updating sql-database-auditing-get-started article
Update install-configure-powershell.md
Delete powershell-azure-resource-manager.md
Updated freshness date and author
Merge branch 'master' of https://github.com/Azure/azure-content
Mobile: fixed iOS node.js push tutorial links and screenshot