You need to install the Wowza IDE plugin into you eclipse install. It doesn't get added as a Referenced Library.
Click on Help & Install New Software.
If you haven already, On the Available Software page, add the Wowza update url by clicking Add and enter the following url
Once added, you should get the listing for the Wowza IDE plugin. Install this and restart Wowza.
When you go to create a new project, you should have an option to create a Wowza Media Server Project. When you select this, you will be prompted to configure your Wowza installation location. This will set the correct jar files in the referenced libraries and also set up a build script and debug & launch options.