THe main features of PHP 5.6:
* Constant scalar expressions.
* Variadic functions and argument unpacking using the ... operator.
* Exponentiation using the ** operator.
* Function and constant importing with the use keyword.
* phpdbg as an interactive integrated debugger SAPI.
* php://input is now reusable, and $HTTP_RAW_POST_DATA is deprecated.
* GMP objects now support operator overloading.
* File uploads larger than 2 gigabytes in size are now accepted.
Please refer for difference from oldre release:http://php.net/migration56.
