Changed autoloading from psr-0 to psr-4.
Added class aliases.
Added TypeUtil.
Minor refactoring.
Fixed phpunit.xml to work with psr-4 autoloading.
Merged ArrayUtil::getElementByKeys and ArrayUtil::getElementByKeyPath into one method and changed the signature.
Added 'ArrayUtil::setElementByKeyPath' and 'ArrayUtil::unsetElementByKeyPath' methods + refactoring and phpdocs.