Add some options to generate Oracle SQL

[atiertant]

• oracle doesn' t support ' AS ' beetwen the tableName and its aliasName => options.explicitTableAs
• oracle doesn' t support aliasName starting whith _ => options.prefixAlias
• oracle need ' instead of " to delimit string value => options.stringDelimiter
• oracle doesn't have a LIMIT criteria and use numbered line to do the same => options.rownum

All default value are configured to genarate the same requests than before.

Correct a bug on SelectBuilder.prototype.processAggregates function,now support columnName in model's attribute.

[mikermcneil]

@atiertant awesome! We're working on setting up a basic test suite for this module-- would you be interested in getting involved?

[atiertant]

@mikermcneil of course,it could help for faster devel and faster code integration.