edition: manual changes

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

crates/printer/src/color.rs

@@ -147,9 +147,6 @@ pub struct ColorSpecs {
 /// A `UserColorSpec` can also be converted to a `termcolor::ColorSpec`:
 ///
 /// ```rust
-/// extern crate grep_printer;
-/// extern crate termcolor;
-///
 /// # fn main() {
 /// use termcolor::{Color, ColorSpec};
 /// use grep_printer::UserColorSpec;

crates/printer/src/lib.rs

@@ -27,10 +27,6 @@ contain matches.
 This example shows how to create a "standard" printer and execute a search.
 
 ```
-extern crate grep_regex;
-extern crate grep_printer;
-extern crate grep_searcher;
-
 use std::error::Error;
 
 use grep_regex::RegexMatcher;
@@ -68,20 +64,6 @@ fn example() -> Result<(), Box<Error>> {
 
 #![deny(missing_docs)]
 
-#[cfg(feature = "serde1")]
-extern crate base64;
-
-
-
-
-
-#[cfg(feature = "serde1")]
-#[macro_use]
-extern crate serde_derive;
-#[cfg(feature = "serde1")]
-extern crate serde_json;
-
-
 pub use crate::color::{
     default_color_specs, ColorError, ColorSpecs, UserColorSpec,
 };

crates/printer/src/stats.rs

@@ -8,7 +8,7 @@ use crate::util::NiceDuration;
 /// When statistics are reported by a printer, they correspond to all searches
 /// executed with that printer.
 #[derive(Clone, Debug, Default, PartialEq, Eq)]
-#[cfg_attr(feature = "serde1", derive(Serialize))]
+#[cfg_attr(feature = "serde1", derive(serde::Serialize))]
 pub struct Stats {
     elapsed: NiceDuration,
     searches: u64,