allow to use reference-only on external-schema tag
don't generate sql if skipSql equal true on parent table
on versionnable behavior, don't generate sql if parent table had skipSql
equal to true
create test for I18n behavior testing skipSql parameter
create test for Versionnable behavior, testing skipSql parameter
Merge pull request #422 from lunika/master

I18n, versionnable and external-schema fix issue