another iteration of API experiments

This relates to issue #9, also see discussion under pull request #12 and #11
moved some common logic out of Convention classes

so ConventionData now has an interface, not so POCO anymore, but we get to have 2LOC conventions
migrated the Project file base conventions

They are pretty nasty to look at, since we're pretty much dealing with raw XML of the .csproj.
We probably want to build some sort of abstraction over that (or use the existing one from Microsoft.MsBuild.something.dll
project clean up

removed non used files/types
moved types around project/namespaces to declutter the intellisense experience
Merge pull request #16 from kkozmic/APIv2Spike

another iteration of API experiments