[PHP] Add support for PHP7.

PHP5's C extension API has changed substantially so you need to use
-php7 to specify you want PHP7 compatible wrappers.
Fixes https://github.com/swig/swig/issues/571

Examples/test-suite/php5/director_thread_runme.php

@@ -0,0 +1,32 @@
+<?php
+
+require "tests.php";
+require "director_thread.php";
+
+# Fails in a ZTS-build of PHP - see: https://github.com/swig/swig/pull/155
+exit(0);
+
+// No new functions
+check::functions(array(millisecondsleep,foo_stop,foo_run,foo_do_foo));
+// No new classes
+check::classes(array(director_thread,Foo));
+// now new vars
+check::globals(array(foo_val));
+
+class Derived extends Foo {
+  function do_foo() {
+    $this->val = $this->val - 1;
+  }
+}
+
+$d = new Derived();
+$d->run();
+
+if ($d->val >= 0) {
+  check::fail($d->val);
+}
+
+$d->stop();
+
+check::done();
+?>