Remove references to deprecated extern crate "foo" as bar syntax

src/doc/grammar.md

@@ -329,7 +329,7 @@ view_item : extern_crate_decl | use_decl ;
 
 ```antlr
 extern_crate_decl : "extern" "crate" crate_name
-crate_name: ident | ( string_lit as ident )
+crate_name: ident | ( ident "as" ident )
 ```
 
 ##### Use declarations

src/doc/reference.md

@@ -752,11 +752,10 @@ provided in the `extern_crate_decl`.
 The external crate is resolved to a specific `soname` at compile time, and a
 runtime linkage requirement to that `soname` is passed to the linker for
 loading at runtime. The `soname` is resolved at compile time by scanning the
-compiler's library path and matching the optional `crateid` provided as a
-string literal against the `crateid` attributes that were declared on the
-external crate when it was compiled. If no `crateid` is provided, a default
-`name` attribute is assumed, equal to the `ident` given in the
-`extern_crate_decl`.
+compiler's library path and matching the optional `crateid` provided against
+the `crateid` attributes that were declared on the external crate when it was
+compiled. If no `crateid` is provided, a default `name` attribute is assumed,
+equal to the `ident` given in the `extern_crate_decl`.
 
 Three examples of `extern crate` declarations:
 

src/librustdoc/html/render.rs

@@ -1643,7 +1643,7 @@ fn item_module(w: &mut fmt::Formatter, cx: &Context,
             clean::ExternCrateItem(ref name, ref src) => {
                 match *src {
                     Some(ref src) => {
-                        try!(write!(w, "<tr><td><code>{}extern crate \"{}\" as {};",
+                        try!(write!(w, "<tr><td><code>{}extern crate {} as {};",
                                     VisSpace(myitem.visibility),
                                     src,
                                     name))