php://filter URL is a feature documented here:
http://php.net/manual/en/wrappers.php.php
Unfortunately, it allows remote control of include() behavior
beyond what many developpers expected, enabling easy dump of
PHP source files. The administrator may want to disable the
feature for security sake, and this option makes that possible.
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.
