Fixed oracle integer/boolean type detection in OracleSchemaManager::_getPortableTableColumnDefinition()

DBAL-62 - There is a diference between maximum length (now 4000, oracle is the smallest possible denominator here) of varchars and the default length (255).

Removing annoying NativePhpunitTask from phing and use <exec> to call tests. Include target test in target build again.

DBAL-61 - Merge patch from milokment to align Oracle Transaction behavior to other drivers (Auto-Commit ON when not in an explicit transation).