Update src/FluentNHibernate/Cfg/Db/DB2Configuration.cs

DB2 Provider is a faster DRDA provider for Informix 11.50+
Update src/FluentNHibernate/Cfg/Db/DB2Configuration.cs
Merge branch 'master' of https://github.com/lodrial/fluent-nhibernate into informixDialect
added test case for informix dialect
Merge branch 'master' of github.com:jagregory/fluent-nhibernate into informixDialect
Merge pull request #248 from chester89/informixDialect

Informix dialect