edition: manual changes

This is mostly just about removing 'extern crate' everywhere and fixing
the fallout.

crates/ignore/src/gitignore.rs

@@ -592,7 +592,7 @@ fn parse_excludes_file(data: &[u8]) -> Option<PathBuf> {
     // N.B. This is the lazy approach, and isn't technically correct, but
     // probably works in more circumstances. I guess we would ideally have
     // a full INI parser. Yuck.
-    lazy_static! {
+    lazy_static::lazy_static! {
         static ref RE: Regex =
             Regex::new(r"(?im)^\s*excludesfile\s*=\s*(.+)\s*$").unwrap();
     };