Implement info command for SysV IPC mqs

The `list` command was refactored a little bit as well and the man
page and readme were updated.

src/sysv/list.rs

@@ -11,9 +11,7 @@ pub struct List {}
 
 impl List {
     pub fn run(&self) -> Result<()> {
-        let file = BufReader::new(File::open("/proc/sysvipc/msg")?);
-
-        for line in file.lines() {
+        for line in BufReader::new(File::open("/proc/sysvipc/msg")?).lines() {
             for field in line?.split_whitespace().collect::<Vec<&str>>() {
                 print!("{0: <10}", field);
             }