Update README.md
Fix creation/delation detection
Merge pull request #67 from KnpLabs/fix/creation-deletion-detection

Fix creation/delation detection
Fix PSR convention
Merge pull request #68 from KnpLabs/fix/psr

Fix PSR convention
Kernel is optionnal
Fix exception issue
Replace unset() by isWritable
Fix property access version

Fix property access version

Fix property access version

Fix property access version