Fix stored proc resolution for non-dbo schema

I was actually facing trouble to properly use stored proc. In a transaction, I found out that the active transaction is not assigned to the stored proc SqlCommand object if I explicitly specify the schema of the stored proc.

The active transaction will be properly assigned if I did not explicitly specify the schema, however this will only work when the schema of the stored proc is dbo.

The options I had, sorted by most preferred to least preferred:
1. Properly assign the active transaction when the schema is explicitly stated - did not figure out how to do this
2. Stored proc lookup should work across all schema when no schema is specified - included in this pull request
3. Change the schema of my stored proc to dbo - pretty much unacceptable