Merge pull request #294 from madaleno/master

updated FirebirdTests to fix transactions use.
Update README.md
Merge pull request #295 from madaleno/master

Add overloaded ByExampleWhere<T>() method with excludeNulls parameter
added schema prefix to JoinSqlBuilder for building queries
Merge pull request #297 from Lee337/master

added schema prefix to JoinSqlBuilder for building queries