embedding: fix string_list deallocation where I accidentally the whole string_list
embedding: fix string_list compile errors?
embedding: add string_map_to_vec() to reduce transmute calls
auto merge of #3785 : zmike/servo/embedding-fixups-for-string_list, r=larsbergstrom

r+ @jdm @larsbergstrom  ?
Update style/README.md - libcss is gone now
Cache last fontgroup. Style recalc on wikipedia/rust 66ms -> 41ms.
Fix build warnings in the cef port.
Make some warnings errors in the cef port.
Really fix #3738 by only processing iframe src attributes during parsing.
auto merge of #3782 : Ms2ger/servo/cef-warnings, r=Ms2ger,metajack
Add layers dependency to util crate. Fixes #3783.
auto merge of #3791 : jdm/servo/moreiframe, r=Ms2ger

....
auto merge of #3792 : samlh/servo/patch-1, r=jdm

Small drive-by update to the style crate readme.
Rename untraceable!() to no_jsmanaged_fields!(). References issue #3671
auto merge of #3773 : rclanan/servo/rename-untraceable, r=jdm
Update rust-layers for android build fix.
Merge pull request #3799 from glennw/update-layers

Update rust-layers and friends for android build fix.
auto merge of #3794 : glennw/servo/font-content-opt, r=pcwalton
Use WindowMethods to get native graphics metadata instead of
relying on azure. This is a prerequisite for the switch to glutin.

Tested on Linux, mac. Tested that android + cef build.
auto merge of #3795 : jdm/servo/utildeps, r=metajack