Removing hard-coded references to c:\work in build events

Hi Govert

Thanks for pulling the array function registration code. I see you got around the problem I was having reflecting the lambda function directly - not sure why i missed that, but thanks.

This is just a small commit to allow the project to compile cleanly in my environment - there were some hard-coded paths to your working directories which caused post-build failures. I guess that this also needs to be fixed in the Excel-DNA nuget installer script, but I haven't taken a look at that...