pandas.read_sql_table doesn't support Oracle Synonyms
From what I can see `read_sql_table` has everything necessary to connect to an Oracle database using an SQLAlchemy connection. Unfortunately, it doesn't support `oracle_resolve_synonyms`. http://docs.sqlalchemy.org/en/latest/dialects/oracle.html#synonym-dblink-reflection That means it's not possible to use synonyms for table names, which I think is pretty common in oracle databases.

It would be cool to add this. How hard would that be? I can work on a PR.
