compilable php7 version

[Lagovas]

• compilable on

$ php --version
PHP 7.2.1 (cli) (built: Jan  3 2018 06:02:01) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2017 Zend Technologies

• pass integration tests php <-> php with secure cell
• splitted code into several files

It's not completed version that can be used to update unit tests. After successful run unit tests with php7 we can be sure that it works correctly

[ignatk]

Cool - lack of php7 support was really holding me back in my branch to migrate to Circle CI 2.0 (as well as newer Ubuntu test-image, because newer Ubuntu provides PHP7 by default).

[vixentael]

Yes, that's super cool!

We'll close #178 issue after we update php5 and php7 unit tests, and probably refactor folder structure a bit, but overall, php7 support is a blast!