Merge pull request #1 from Zache/master

Typo in class name
Improve got/expected event diffs in errors.

Didn't handle the case where the same exception type might be emitted
multiple times properly.
Add EventStore implementation of IEventStore.

Uses the EventStore from http://geteventstore.com/.
Add note about EventStore.ClientAPI dependency.
Add SQL script for SQL-based event store.

So folks don't have to reverse-engineer it from the code.