Modify Linux travis config to run content and cpu ref tests.
Port attribute name to use atom.
Add support for showing debug borders

This can help debug issues with the compositor and show when a page is
creating layers.
Merge pull request #2912 from mrobinson/debug-borders

Add support for showing debug borders
Merge pull request #2904 from glennw/linux-ref-test

Modify Linux travis config to run content and cpu ref tests.
Convert to atom earlier in SetAttributeNS
Add explicit cast from size_t to u64.

Fixes compile error on non-64-bit targets.
Fix compile error and warning on Android
Update to latest string-cache.

Includes fix for servo/string-cache#4.
Exclude host libs from Android package.

Fixes startup error caused by packaging the wrong libphf.so.
Basic implementation of CORS
Update comments about Node::layout_data
Implement very basic canvas rendering context logic. No visual display present.
Merge pull request #2911 from glennw/atom-attr-name

Port attribute name to use atom; r=Ms2ger
Merge pull request #2794 from Manishearth/cors

Basic implementation of CORS; r=jdm
Add doc and doc-$(crate) targets to the Makefile using rustdoc.
Merge pull request #2920 from Ms2ger/canvas

Implement very basic canvas rendering context logic. No visual display present.
Merge pull request #2918 from mbrubeck/size_t

Fix build errors for Android (and other 32-bit targets)
Escape HTML in the cors.rs documentation.

Rustdoc passes the code straight through, leading to poor generated HTML.
Merge pull request #2923 from Ms2ger/cors-escape

Escape HTML in the cors.rs documentation.