Merge branch 'v0.6.x' into master

# Conflicts:
#	serde/Cargo.toml
#	serde/src/ser/impls.rs
#	serde_codegen/src/attr.rs
#	serde_codegen/src/de.rs
#	serde_codegen/src/field.rs
#	serde_codegen/src/ser.rs

serde_tests/tests/test.rs

@@ -1,3 +1,6 @@
+#![cfg_attr(feature = "nightly", feature(plugin))]
+#![cfg_attr(feature = "nightly", plugin(clippy))]
+
 extern crate num;
 extern crate serde;
 

serde_tests/tests/test_de.rs

@@ -99,12 +99,12 @@ declare_tests! {
     test_char {
         'a' => vec![Token::Char('a')],
         'a' => vec![Token::Str("a")],
-        'a' => vec![Token::String("a".to_string())],
+        'a' => vec![Token::String("a".to_owned())],
     }
     test_string {
-        "abc".to_string() => vec![Token::Str("abc")],
-        "abc".to_string() => vec![Token::String("abc".to_string())],
-        "a".to_string() => vec![Token::Char('a')],
+        "abc".to_owned() => vec![Token::Str("abc")],
+        "abc".to_owned() => vec![Token::String("abc".to_owned())],
+        "a".to_owned() => vec![Token::Char('a')],
     }
     test_option {
         None::<i32> => vec![Token::Unit],

serde_tests/tests/test_ser.rs

@@ -63,7 +63,7 @@ declare_ser_tests! {
     }
     test_str {
         "abc" => &[Token::Str("abc")],
-        "abc".to_string() => &[Token::Str("abc")],
+        "abc".to_owned() => &[Token::Str("abc")],
     }
     test_option {
         None::<i32> => &[Token::Option(false)],

serde_tests/tests/token.rs

@@ -326,7 +326,7 @@ impl de::Error for Error {
     fn end_of_stream() -> Error { Error::EndOfStreamError }
 
     fn unknown_field(field: &str) -> Error {
-        Error::UnknownFieldError(field.to_string())
+        Error::UnknownFieldError(field.to_owned())
     }
 
     fn missing_field(field: &'static str) -> Error {
@@ -396,7 +396,6 @@ impl<I> de::Deserializer for Deserializer<I>
     fn deserialize<V>(&mut self, mut visitor: V) -> Result<V::Value, Error>
         where V: de::Visitor,
     {
-        println!("visit {:?}", self.tokens.peek());
         match self.tokens.next() {
             Some(Token::Bool(v)) => visitor.visit_bool(v),
             Some(Token::Isize(v)) => visitor.visit_isize(v),