Include additional documentation samples to relate extension methods to async/await behavior
Simplify the CompletedTask methods for .NET 4.5+
Use VoidResult instead of object where appropriate
Generate XML documentation for test projects
Merge pull request #51 from sharwell/test-project-docs

Generate XML documentation for test projects
Merge pull request #52 from sharwell/simplify

Simplifications
Merge pull request #36 from sharwell/examples

Include additional documentation samples
Implement support for exception handling continuations (fixes #33)
Add description of `Catch` methods to the User Guide
Add unit tests for `Catch` methods