Replace a.get(n) with a[n].
Avoid mutation in a match guard.
Remove impl Seek for MemWriterFakeStream.

Its seekability wasn’t being used, and so in light of the changes made
in rust-lang/rust#15915 it should be removed, rather than switching from
the now-unseekable ``MemWriter`` to the new ``SeekableMemWriter``.

This necessitated adding the ``get_ref`` method which was added to
``MemWriter`` at some point.
Fix build for certain BSD systems

* BSD's don't have bash in this location. /bin/sh works here perfectly.
* BSD's have GNU make as gmake. Test for it and use it accordingly.
Merge pull request #117 from mneumann/master

Fix build for certain BSD systems
Merge remote-tracking branch 'refs/remotes/upstream/master' into servo
Upgrade to rust-url with renamed crate.
Merge pull request #26 from servo/rustup-20140804

Upgrade Rust.