Moved Databases.xml to conf folder and this configuration file will not be packed into jar.

As Databases.xml is designed as an user-defined configuration file, so
we had better leave it out of the jar. And for better usage, we leave
the Databases.xsd in conf folder for reference.
Fixed bug: removed database information from cache by databaseName
Fixed Bug: rs.getString(colName) sometimes will return "", not null.
Added unit test for CloneDatabaseSchema method
Added findDatabaseInformation method to get database information
Fix Bug: String value should be wrapped by single quote.
Added lowerCaseTableNames property for indentifing whether table name should be stored in case-sensitive.