Cleaned up example building helpers
Created System.Object.Should extension method

In an attempt to reduce noice when executing assertions against data
stored in test context. E.g:

    ctx |> TestContext.getSubject |> should (be.EqualTo 1)

becomes

    ctx.Subject.Should (be.EqualTo 1)
Added System.Object.ShouldNot extensions
Reduced code duplication in RunnerSpecs

Wrapped repetive run |> ignore -> verify recorded calls into single
function. This reduces the examples to describe example groups, and in
which order things should execute, without specifying how examples are
run.
TestRunnerSpecs takes advantage of Should extension
Added be.True and be.False matchers