replace strings index fix

allow replace strings with adjacent text like "$1ies" "$1s"

Author: nathanfaucett

src/re.rs

@@ -780,7 +780,7 @@ impl<'t> Captures<'t> {
     pub fn expand(&self, text: &str) -> String {
         // How evil can you get?
         // FIXME: Don't use regexes for this. It's completely unnecessary.
-        let re = Regex::new(r"(^|[^$]|\b)\$(\w+)").unwrap();
+        let re = Regex::new(r"(^|[^$]|\b)\$(\d+|\w+)").unwrap();
         let text = re.replace_all(text, |refs: &Captures| -> String {
             let pre = refs.at(1).unwrap_or("");
             let name = refs.at(2).unwrap_or("");