add support for custom version_static.txt for package maintainers

include/version.php

@@ -1,12 +1,18 @@
 <?php
 
+	/* for package maintainers who don't use git: if version_static.txt exists in tt-rss root
+		directory, its contents are displayed instead of git commit-based version, this could be generated
+		based on source git tree commit used when creating the package */
+
 	function get_version(&$git_commit = false, &$git_timestamp = false) {
 		$version = "UNKNOWN (Unsupported)";
 
 		date_default_timezone_set('UTC');
 		$root_dir = dirname(dirname(__FILE__));
 
-		if (is_dir("$root_dir/.git")) {
+		if (file_exists("$root_dir/version_static.txt")) {
+			$version = file_get_contents("$root_dir/version_static.txt") . " (Unsupported)";
+		} else if (is_dir("$root_dir/.git")) {
 			$rc = 0;
 			$output = [];