Drop event listener exceptions on the floor.

We get a lot of failures from assertions that event listeners haven't
thrown exceptions. As the FIXME above these assertions suggests, we
should just drop them on the floor.
auto merge of #2582 : zwarich/servo/drop-exceptions, r=jdm

We get a lot of failures from assertions that event listeners haven't
thrown exceptions. As the FIXME above these assertions suggests, we
should just drop them on the floor.
Reduce the number of times we call rustc in our Makefile #2327
Upgrade Rust.
auto merge of #2538 : mozilla/servo/rustup-20140528, r=SimonSapin

Not yet ready for merge, but you can start reviewing.

Still need to fix linux and some make check code.
auto merge of #2586 : ebalint/servo/2327, r=jdm
gfx: Add display list optimization to eliminate clipped items before
submitting them to Skia.

40x improvement in painting time on Wikipedia.
auto merge of #2588 : pcwalton/servo/display-list-optimization, r=glennw

submitting them to Skia.

40x improvement in painting time on Wikipedia.

r? @glennw
JSON response support and some default headers