Updated RabbitHutch outdated method comments.

EasyNetQ.CreateBus(string connectionString) and
EasyNetQ.CreateBus(string connectionString, Action<IServiceRegister>
registerServices) were mentioning that, if not specified, the default
requestedHeartbeat would be 0. This is incorrect, the default value is
set in EasyNetQ.ConnectionConfiguration ctor “RequestedHeartbeat = 10;”
Updated RabbitHutch broken xml tags

There were some &lt; and &gt; lying around, replaced with proper use of
curly brackets to designate generics.
Merge pull request #331 from mleenhardt/RabbitHutch-doc-update

RabbitHutch comments update