Close #84

Actually <img> elements in <noscript> are not prefetched anymore.

Probably because html5ever already parses the <noscript> content as raw
text data if `scripting_enabled` is activated.

See
https://github.com/servo/html5ever/blob/servo/src/tree_builder/rules.rs#
L126

Also, added a test to the images cache.
Enable the cors/ wpt subset

Fixes #3781
Remove unnecessary import of libgreen
auto merge of #3958 : zwarich/servo/remove-libgreen, r=Ms2ger
Change /cors/remote-origin.htm.ini to CRASH
auto merge of #3952 : andrewguertin/servo/wpt-cors, r=Manishearth

Fixes #3781 

I had to make a small fix to wptrunner's wptupdate, but otherwise the instructions at https://github.com/servo/servo/blob/master/tests/wpt/README.md#updating-test-expectations were good and this was very straightforward.
Clip display list based on frame viewport

Instead of creating a display list for the entire page, only create one
for an area that expands around the viewport. On my machine this makes
incremental layout of http://timecube.com 50% faster.
auto merge of #3934 : guillaumebort/servo/fix/84, r=jdm

Actually `<img>` elements in `<noscript>` are not prefetched anymore.

Probably because html5ever already parses the `<noscript>` content as raw
text data if `scripting_enabled` is activated.

See https://github.com/servo/html5ever/blob/servo/src/tree_builder/rules.rs#L126

Also, added a test to the images cache.
Rename LoadIframeUrlMsg to CreateIFrameAndLoadUrlMsg

This better reflects what the message does.
Small fix to variable name

This is a more accurate name for the script pipeline.
Add some factory methods for frame tree types
Send incremental frame tree updates to the compositor

This allows the compositor to add frames after the call to SetIds,
where the initial frame tree is created. There are still some issues
preventing proper late frame creation, but this prevents crashes when
it happens.

Fixes #3738.
auto merge of #3951 : mrobinson/servo/iframes, r=jdm

This is the first step to allowing incremental iframe creation and destruction. This should eliminate task failures when an iframe is added to the frame tree lazily via script.
Move code related to json packet reading to JsonPacketSender trait

fixup! Move code related to json packet reading to JsonPacketSender trait
Fix #3933
auto merge of #3955 : thiagopnts/servo/devtools-refactoring, r=jdm

I was messing around devtools code and saw some TODOs, is anyone working on it? I took one of them:

```// TODO: this really belongs in the protocol module.```

I would be glad to help with this if no one is on it already, just let me know.
auto merge of #3938 : guillaumebort/servo/fix/3933, r=jdm

Implement HTMLOptionElement.{label,value}
auto merge of #3809 : mrobinson/servo/display-list-optimization, r=pcwalton

Instead of creating a display list for the entire page, only create one
for an area that expands around the viewport. On my machine this makes
incremental layout of http://timecube.com 50% faster.
Rust upgrade to rustc hash b03a2755193cd756583bcf5831cf4545d75ecb8a
Fix unit test compile error.