Can't open sqlproj with Visual Studio 2012? Install SQL Server Data Tools.

I recently updated to Visual Studio 2012 Ultimate.
When i tried to open an existing SQL Server SQLCLR Project (*.sqlproj), it says that the sqlproj is incompatible with the version I am running.

How-i-fixed-it:
I installed the SQL Server Data Tools from http://msdn.microsoft.com/en-us/data/tools.aspx.

I found the solution here:

http://stackoverflow.com/questions/11906691/visual-studio-2012-csproj-and-sqlproj

and here:
http://www.comoke.com/index.php/2012/10/visual-studio-2012-database-project-sqlproj-project-type-not-supported/

and here:
http://blog.tentaclesoftware.com/archive/2013/02/11/visual-studio-2010-and-2012-sqlproj-interoperability.aspx