Update XmlSubscriptionStorage.cs

The old code assumes there's a directory in the path, which might not be true. Fixed so it works even without a directory in the path.

Ex: "subscriptions.xml" doesn't work, but ".\subscriptions.xml" works.

Another method could be to throw a meaningful exception if dir is null/empty.
Merge pull request #212 from hagbarddenstore/patch-1

Update XmlSubscriptionStorage.cs
updated changelog with @hagbarddenstore's fix
made Rabbit transport throw out its subscription and underlying model when end-of-stream is detected
updated changelog
updated version to 0.54.3 - I wonder what 0.54.2 is?
updated changelog with dummy entry
implemented load balancer
added nuspec for MSMQ load balancer
added nuspec to sln
added @jasperdk 's test
made fix
changed test setup to be more refactoring-friendly
updated changelog
Merge branch 'feature-msmqloadbalancer'
added load balancer
better cleanup after test
updated changelog
fixed format string in load balancer's logging
update changelog