Merge pull request #203 from jasperdk/master

TransactionContext [ThreadStatic] and ASP.NET is actually a problem
added some 'belt & suspenders' to ambient tx ctx
updated changelog
added necessary serialization ctors to exceptions
RebusBus.ToString and make SetNumberOfWorkers re-entrant
optimized data structure used by HeaderContext with hash code-based pre-lookup
added entry to changelog
added multi-threaded header context stress test and limited the number of buckets
made stress test parameterized and added test cases
ALT + ENTER
removed unused properties
added comments
proper handling of queue exception + factored backoff-like functionality out into proper helper thingie
updated changelog
increased Azure wait times when throttling is detected
updated changelog
added a bunch of comments to Rabbit transport
updated Rebus deps in showdown
reformatted
increased print interval to 10 s