Add define encrypt

تم أضافة ثابت جديد 
encrypt 

لان لو تم الاستخدام هكذا 
cliprz::system(encrypt)->...

فلن يعرفه ك ثابت 

Notice: Use of undefined constant encrypt - assumed 'encrypt'

:)
Merge pull request #22 from alaa13212/fix-errors

FIX: check file type in simple upload library
Merge pull request #21 from ameralrdadi/master

Add define encrypt
Edit $kyes to $keys
Update session.php
Merge pull request #23 from ameralrdadi/master

Edit $kyes and filename.php
Update README.md

Add Ali M. Al-brrak and Amer Alrdadi as 2.0.0 Developers
2.0.0 Beta 2