Use debugger non user code attribute

[garyhuntddn]

Introduce new property that can be used in the OutputFile derived classes to dictate whether to include the DebuggerNonUserCode attribute in generated code.

Added this to the build task and associated classes and to the documentation.

I've not implemented it in the same way as abstract was implemented it as it would have meant introducing multiple properties (in Lexer and Parser) to do the same thing. Obviously happy to change this if that is the preferred option.

Closes #106

[garyhuntddn]

PS reason for the new PR is that I screwed up my fork with a bunch of merge commits that aren't relevant