Examples

Fixes #15 

Outstanding work:

 - [x] Clean up, fix and improve NetToString logic
 - [x] Overload for `WithExamples` with tabular verbatim string example?
 - [x] Allow for multi-word examples
 - [x] Reflective API
 - [x] In reflective API the examples should be injected into properties
 - [x] Allow injection into private and protected fields and properties (for both APIs)
 - [x] Fluent API
 - [x] Html Report
 - [x] Metro Html Report
 - [x] Markdown Report (PR Open)
 - [x] Console Report
 - [ ] Diagnostics Report
 - [x] Tests!
 - [x] More samples of using Example API to the Samples project
 - [x] Fluent Should replace example args in step. i.e `GivenTheForceIs(ForceLevel)` should have step name of `Given the force level is <force level>` if there is an example with Header of `Force Level`
 - [x] Related, if the property is passed, I should not need a placeholder, i.e `GivenTheForceIs__ForceLevel__`
 - [x] Throw error if we cannot find anywhere to put example value. It should go *somewhere*, otherwise small mispellings will be hard to find
 - [ ] ExecutableAttributeStepScanner does not look like it works with examples?
 - [x] Allow assertion steps to all execute when grouped together (PR Open)