Update function «Where»
Arrays now is not supported
Values ​​are set in the second parameter
Improvement operations
Removed static type for instance and sth variables
Started implementation of #3 («extra» function)
Removed _where()
Added _extra()
$where replaced (Array)$extra with item, called «where»
Create .gitattributes with export-ignore
Fixed issue #2 (Exception if update used without where)