Enabling debugging

This enables debugging for:
* Classes/lambdas included in External cx/csx files
* C# classes/lambdas embedded in the javascript

This is enabled by:
* Turning on IncludeDebugInformation in the parameters passed to the Codedom compiler
* Including #line directives at the top of the file for classes and just before the code declaring a Func<object, Task<object>> in the case of lambdas

Debugging of embedded c# code is dependent upon a change to edge to pass through jsFileName and jsLineNumber parameters corresponding to where this code is within the javascript file.

ref: tjanczuk/edge#6