Implement window.atob/btoa
Make Attr::local_name an Atom.
Pass an Atom to before_remove_attr and after_set_attr.
Prevent margin collapse in the root flow

According to the CSS specification, section 8.3.1, margins of the root
element's box do not collapse. Ensure that root flow margins do not
collapse during the assign heights phase.
Add doge Servo files for testing and demos
Merge pull request #3107 from mrobinson/root-margin-collapse

Prevent margin collapse in the root flow
Merge pull request #3109 from larsbergstrom/doge_files

Add doge Servo files for testing and demos
Replace hasInterfacePrototypeObject checks by isCallback checks in codegen.

Checking for callbacks directly makes it a lot clearer what's going on, and we
don't intend to take hasConcreteDescendant into consideration.

See also <https://bugzilla.mozilla.org/show_bug.cgi?id=1026720>.
Add a script to update the WebIDL parser.
Update WebIDL.py.
Stop artificially constraining the size of the GC heap.
Merge pull request #3113 from Ms2ger/update-webidl

Update WebIDL.py; r=Manishearth
Merge pull request #3112 from Ms2ger/hasInterfacePrototypeObject

Replace hasInterfacePrototypeObject checks by isCallback checks in codegen.
Add a documentation comment for CGWrapMethod.
Cleanup the File::open_mode call.
Cleanup formatting in reftest.rs.
Merge pull request #3099 from Ms2ger/attr-local_name-atom

Make Attr::local_name an Atom; r=abinader
Merge pull request #3114 from Ms2ger/gc-max-bytes

Stop artificially constraining the size of the GC heap; r=larsberg
Merge pull request #3115 from Ms2ger/CGWrapMethod-doc

Add a documentation comment for CGWrapMethod; r=Manishearth
Merge pull request #3116 from Ms2ger/format-reftests

Cleanup formatting in reftest.rs; r=jack