[contrib] Place script for fetching contributors from GitHub's gist to contrib directory

No need to depend on gist.github.com

README.md

@@ -108,7 +108,7 @@ We are RSS-Bridge community, a group of developers continuing the project initia
 **Contributors** (sorted alphabetically):
 <!--
 Use this script to generate the list automatically (using the GitHub API):
-https://gist.github.com/LogMANOriginal/da00cd1e5f0ca31cef8e193509b17fd8
+./contrib/prepare_release/fetch_contributors.php
 -->
 
 * [16mhz](https://github.com/16mhz)

contrib/prepare_release/fetch_contributors.php

@@ -0,0 +1,94 @@
+<?php
+/* Generate the "Contributors" list for README.md automatically utilizing the GitHub API */
+
+$url = 'https://api.github.com/repos/rss-bridge/rss-bridge/contributors';
+$contributors = array();
+$next = true;
+
+while($next) { /* Collect all contributors */
+
+	$c = curl_init();
+
+	curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);
+	curl_setopt($c, CURLOPT_HTTPHEADER, array(
+			'Accept: application/json',
+			'Content-Type: application/json',
+			'User-Agent: RSS-Bridge'
+			));
+	curl_setopt($c, CURLOPT_URL, $url);
+	curl_setopt($c, CURLOPT_HEADER, true);
+
+	$data = curl_exec($c);
+
+	$headerSize = curl_getinfo($c, CURLINFO_HEADER_SIZE);
+	$header = substr($data, 0, $headerSize);
+	$headers = parseResponseHeader($header);
+
+	curl_close($c);
+
+	foreach(json_decode(substr($data, $headerSize)) as $contributor)
+		$contributors[] = $contributor;
+
+	// Extract links to "next", "last", etc...
+	$links = explode(',', $headers[0]['link']);
+	$next = false;
+
+	// Check if there is a link with 'rel="next"'
+	foreach($links as $link) {
+		list($url, $type) = explode(';', $link, 2);
+
+		if(trim($type) === 'rel="next"'){
+			$url = trim(preg_replace('/([<>])/', '', $url));
+			$next = true;
+			break;
+		}
+	}
+
+}
+
+/* Example JSON data: https://api.github.com/repos/rss-bridge/rss-bridge/contributors */
+
+// We want contributors sorted by name
+usort($contributors, function($a, $b){
+	return strcasecmp($a->login, $b->login);
+});
+
+// Export as Markdown list
+foreach($contributors as $contributor) {
+	echo "  * [{$contributor->login}]({$contributor->html_url})\n";
+}
+
+/**
+ * Parses the provided response header into an associative array
+ *
+ * Based on https://stackoverflow.com/a/18682872
+ */
+function parseResponseHeader($header) {
+
+	$headers = array();
+	$requests = explode("\r\n\r\n", trim($header));
+
+	foreach ($requests as $request) {
+
+		$header = array();
+
+		foreach (explode("\r\n", $request) as $i => $line) {
+
+			if($i === 0) {
+				$header['http_code'] = $line;
+			} else {
+
+				list ($key, $value) = explode(': ', $line);
+				$header[$key] = $value;
+
+			}
+
+		}
+
+		$headers[] = $header;
+
+	}
+
+	return $headers;
+
+}