Do not pass '--no-init' on newer less versions

With this change, we do not pass the `--no-init` option in newer
versions of less (530 or higher).

This fixes #749

src/less.rs

@@ -0,0 +1,49 @@
+use std::process::Command;
+
+pub fn retrieve_less_version() -> Option<usize> {
+    let cmd = Command::new("less").arg("--version").output().ok()?;
+    parse_less_version(&cmd.stdout)
+}
+
+fn parse_less_version(output: &[u8]) -> Option<usize> {
+    if output.starts_with(b"less ") {
+        let version = std::str::from_utf8(&output[5..]).ok()?;
+        let end = version.find(' ')?;
+        version[..end].parse::<usize>().ok()
+    } else {
+        None
+    }
+}
+
+#[test]
+fn test_parse_less_version_487() {
+    let output = b"less 487 (GNU regular expressions)
+Copyright (C) 1984-2016  Mark Nudelman
+
+less comes with NO WARRANTY, to the extent permitted by law.
+For information about the terms of redistribution,
+see the file named README in the less distribution.
+Homepage: http://www.greenwoodsoftware.com/less";
+
+    assert_eq!(Some(487), parse_less_version(output));
+}
+
+#[test]
+fn test_parse_less_version_551() {
+    let output = b"less 551 (PCRE regular expressions)
+Copyright (C) 1984-2019  Mark Nudelman
+
+less comes with NO WARRANTY, to the extent permitted by law.
+For information about the terms of redistribution,
+see the file named README in the less distribution.
+Home page: http://www.greenwoodsoftware.com/less";
+
+    assert_eq!(Some(551), parse_less_version(output));
+}
+
+#[test]
+fn test_parse_less_version_wrong_program() {
+    let output = b"more from util-linux 2.34";
+
+    assert_eq!(None, parse_less_version(output));
+}