Update Singleton trait & test

PSR-1 & 2
Improved namespace
Update Settings class & test

PSR-1 & 2
New functionality: size(), isEmpty(), clear()
Add Observer pattern & test
Update Event class & test

PSR-1 & 2
Observer pattern
Update MVC pattern

PSR-1 & 2
Improved namespace
Update File class

PSR-1 & 2
Update URL class & test

PSR-1 & 2
Simplified encode and decode
Update Session class & test

PSR-1 & 2
New functionality: size(), isEmpty(), clear()
Update Request class & test

PSR-1 & 2
New functionality: size(), isEmpty(), containsKey(), containsValue()
Update Response class & test

PSR-1 & 2
New functionality: size(), isEmpty(), clear()
{@inheritdoc}
Update Router class & test
Update Observer pattern & test
Add Logger, LogRecord & LogHandler
Continuous Integration
Update read me
Update composer

Renamed package
Require PHP 5.4 & Psr/Log
YAML file cannot contain tabs
Update Request class

Fixed a small comment
Update File class

Fixed getDirectory & getName bug