Fixs, and new Config and Database proposal.

Basically following changes made:

Changed a little bit database class for multi-database purpose.
Config is flexible now, you can create few configs and get keys from ini files (yet only ini, however, planning to do PHP and database configs), main config can be get across app via \core\config::getConfig().

Database is depend on config, thanks!

P.S.: sorry for several commits, couldn't get how to rebase them