Add "using Abp.Web.Configuration" statement

Several people are asking - what is the right way to debug ABP solutions.

I've found in comments your advice about adding PDB from symbolsource.org - it's very useful.
You've also mentioned this method to turn off sending exceptions to client (although it didn't help me :)) - now it's in Startup article and it's not expected to check this article for debugging questions...

Imho, it's good idea to add some advices to debug framework in separate article...