Sample IList test fixture project and updated documentation

Added sample test fixture project targeting IList<T> implementations for performance testing several IList operations: Add, Insert, Count, Clear, Contains and Remove.
Added images with the result charts of test executions comparing .NET BCL IList<T> implementations agains C5 Library ones.
The documentation in README file was updated, even though it is not yet finished. I want to comment and review the style before finishing it.