* Add tests for more Permissions code coverage

* Add guild tests

* Add more in-depth covering of permissions methods

* Add tests for OverwritePermissions

* Remove unknown ItemGroup tag from csproj

* Add missing Fact attributes, separate class so that it is not dependant on main test fixture

* Separate out GuildPermissions and ChannelPermissions tests from main partial Tests class because they do not need to have access to the main test fixture

* Start on API analyzers

* Finish GuildAccessAnalyzer

* Update build script (will this do?)

* Correct slashes

* Extrapolate DerivesFromModuleBase() to an extension method

* Quick refactoring

* Add doc file