libsyntax: don't parse ////, /***/ as doc comments
made licenseck.py work for year substitutions
Remove DVec from syntax::parse
Remove DVec from check_const
Remove DVec from json
Remove DVec from workcache
librustc: Replace `impl Type : Trait` with `impl Trait for Type`. rs=implflipping
Remove all final references to die!
librustc: Replace `impl Type : Trait` with `impl Trait for Type`. rs=implflipping
auto merge of #4932 : pcwalton/rust/implflipping, r=pcwalton

...lflipping
auto merge of #4934 : nickdesaulniers/rust/issue4524cleanup, r=brson

review? @brson
Issue #4524
auto merge of #4911 : lifthrasiir/rust/comment-exemptions, r=catamorphism

This is a natural extension of #4887, and handles the following three cases:

~~~~
a line with only /s
////////////////////////////////////////////

a line with only /s followed by whitespace
////////////////////////////////////////////         

a block comment with only *s between two /s
/********************************/
~~~~
auto merge of #4927 : sanxiyn/rust/remove-dvec, r=catamorphism