fix in Resource loading utils class to avoid using the filesystem

Here is a little fix in your Resource util class.

This is a simple fix that change the order the search is done to find a resource.
Before this fix, a resource was searched first in the filesystem, then in the classpath.

This caused me some trouble with the platform as a service (Google AppEngine) I am using, because I am not allowed to use the filesystem.

Also, maybe, this bit of code will run a little faster since, at runtime, the majority of resource we want to load is in the classpath anyway.

I run all the tests, everything was green.

Let me know what you think!

Thank you