auto merge of #558 : tkuehn/servo/master, r=metajack

* constellation grants permission to renderers instead of passing tokens
* render tasks wrap layer buffer sets in ARCs
* removed no-longer-used field (constellation chan) from render task struct
Add glfw and glfw-rs to servo build.
Fix clean targets.
Replace glut with glfw.

Also fixes initial window size to get based on the windowing code instead of
being hardcoded everywhere. This code works on HiDPI displays, but does not
appropriately scale the output up yet.
Make contenttest harness build again.
auto merge of #564 : jdm/servo/contenttest, r=metajack
Derive more Eq implementations

Fixes #181.
Update to latest Rust.
auto merge of #566 : kmcallister/servo/derive-eq, r=metajack

Fixes #181.
Add Makefile trigger for forcing clean-rust to happen.
auto merge of #563 : metajack/servo/glfw, r=metajack

This code replaces glut with glfw. The motivation here is address the GPU driver bugs on Linux when using multiple `Display *` pointers with shared GL contexts instead of a single common one. GLFW has native access methods which provide access to its `Display *`, which appears to be unique among all the similar toolkits.

Details:
- Adds glfw and glfw-rs to the build
- Removes GLUT code and replaces it with GLFW versions
- Fixes hard coded initial window values
- Fixes clean targets
- Event loop doesn't block on windowing events anymore
Added new dependencies and info about keyboard shortcuts and make targets.
Added note about `make bindings`.
auto merge of #567 : metajack/servo/more-to-read, r=jdm

...s.
mildly cleaner profiling code in util::time
scripts from inactive pipelines resize upon navigating to their pages