auto merge of #5861 : catamorphism/rust/rustpkg, r=catamorphism

r? @graydon

Pulled out tests into their own modules inside the files they test,
as per the draft style guidelines.

Started a new module, path_util, for utility functions to do with
paths and directories.

Changed default_dest_dir to use a condition and return Path
instead of Option<Path>.

diff --cc src/librustpkg/rustpkg.rc
index 83f5c78af43549c87fa9282f84eff67dde361a15,d61fe30992d8514a2a0ff93193f8b5ae0fe4a869..f8805142769c14cc98e1d57b05ef4c995d19cdde
--- 1/src/librustpkg/rustpkg.rc
--- 2/src/librustpkg/rustpkg.rc
+++ b/src/librustpkg/rustpkg.rc
@@@ -8,10 -8,10 +8,10 @@@
  // option. This file may not be copied, modified, or distributed
  // except according to those terms.
  
- // rustpkg - a purely function package manager and build system
+ // rustpkg - a package manager and build system for Rust
  
  #[link(name = "rustpkg",
 -       vers = "0.6",
 +       vers = "0.7-pre",
         uuid = "25de5e6e-279e-4a20-845c-4cabae92daaf",
         url = "https://github.com/mozilla/rust/tree/master/src/librustpkg")];
  

diff --cc src/librustpkg/util.rs
Simple merge