ELMAH setup
After installing ELMAH.MVC using NuGet, you need to add two verb lines.
web.config:
http://stackoverflow.com/questions/933554/elmah-not-working-with-asp-net-site/1175023#1175023
ELMAH setup for Web API
Install Elmah.Contrib.WebApi using NuGet and add this line on WebApiConfig.cs.
http://blogs.msdn.com/b/webdev/archive/2012/11/16/capturing-unhandled-exceptions-in-asp-net-web-api-s-with-elmah.aspx
https://github.com/rdingwall/elmah-contrib-webapi