refactor: Move install to php53 branch if running an unsupported version of PHP (#8042)

* Move install to php53 branch if running an unsupport version of PHP

* Update validate

* Move PHP version check after update check.  This will prevent us from moving no update users to the php53 branch.

Hopefully if daily.php -f update fails it returns a non-zero and we can move them to the php53 branch still.

* Wiggle things around more.

* Also, send release installs to the php53 branch.

* Set notification error for old PHP version.

scripts/composer_wrapper.php

@@ -0,0 +1,71 @@
+#!/usr/bin/env php
+<?php
+/**
+ * composer_wrapper.php
+ *
+ * Wrapper for composer to use system provided composer or download and use composer.phar
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * @package    LibreNMS
+ * @link       http://librenms.org
+ * @copyright  2017 Tony Murray
+ * @author     Tony Murray <murraytony@gmail.com>
+ */
+
+$install_dir = realpath(__DIR__ . '/..');
+chdir($install_dir);
+
+// Set up proxy if needed
+$proxy = getenv("HTTP_PROXY") ?: getenv("http_proxy");
+if (!$proxy && $proxy = rtrim(shell_exec('git config --global --get http.proxy'))) {
+    // Use git http.proxy if available
+    putenv("HTTP_PROXY=$proxy");
+}
+
+$exec = false;
+
+$path_exec = shell_exec("which composer 2> /dev/null");
+if (!empty($path_exec)) {
+    $exec = trim($path_exec);
+} elseif (is_file($install_dir . '/composer.phar')) {
+    $exec = 'php ' . $install_dir . '/composer.phar';
+} else {
+    if ($proxy) {
+        $stream_default_opts = array(
+            'http' => array(
+                'proxy' => str_replace('http://', 'tcp://', $proxy),
+                'request_fulluri' => true,
+            )
+        );
+
+        stream_context_set_default($stream_default_opts);
+    }
+
+    // Download composer.phar (code from the composer web site)
+    $sha = trim(file_get_contents('http://composer.github.io/installer.sig'));
+    @copy('http://getcomposer.org/installer', 'composer-setup.php');
+    if (@hash_file('SHA384', 'composer-setup.php') === $sha) {
+        // Installer verified
+        shell_exec('php composer-setup.php');
+        $exec = 'php ' . $install_dir . '/composer.phar';
+    }
+    @unlink('composer-setup.php');
+}
+
+if ($exec) {
+    passthru("$exec " . implode(' ', array_splice($argv, 1)) . ' 2>&1');
+} else {
+    echo "Composer not available, please manually install composer.\n";
+}