Oracle JDBC driver to 12cR1 (12.1.0.1)

- Replaced old OJDBC drivers with the newest Oracle JDBC driver.
http://download.oracle.com/otn/utilities_drivers/jdbc/121010/ojdbc6.jar
Fixed Oracle TPCC workload

- Added <dbtype> to example config, otherwise this results in a
NullPointerException.
Fixed Oracle Wikipedia workload

Fixed multiple issues:
- Fixed DDL script, had some wrong field sizes and wrong table names
- Oracle handles quoted object identifiers differently. For example, 'customer'
and '"customer"' are not the same tables. Now the INSERT statements are
generated again if the DB is Oracle.
- Also, Oracle handles an empty string ("") as a NULL value. This breaks things
when inserting an empty string into a column with a NOT NULL constraint. Now
the generated strings are always guaranteed to be at least one character long.
Cleaned up unprintable characters from DDL file
Merge pull request #74 from simonkrenger/oracle-fixes

Oracle updates and benchmark fixes