Conventional ❤ Linux (#68)
* Ensures KnownPaths operates in an OS independent way
* Adds database test category for filtering out db tests on linux build
* Fixes test assembly path specification
* Makes Directory extension methods to be OS agnostic
* Makes assertions for files OS agnostic
* Makes path separators in lots of places OS agnostic
* Makes project file inclusion inspection OS agnostic
* More project file inclusion fixes
* More test fixing
* Makes Cecil AssemblyResolver work for Linux
* Make test assertions more resilient to environment differences
* Fix ThisAssembly test assertion to be OS agnostic
