Use an enum to set set_timeout_or_interval's is_interval field. Fixes #4059
remove comments now that we have more descriptive names
layout: Fix De Morgan's Law error in incremental reflow, allowing
float/absolute layout layout to be idempotent again.

Fixes the maze solver.
auto merge of #4066 : pcwalton/servo/float-incremental-layout-fix, r=cgaebel,cgaebel,cgaebel

Fixes the maze solver.

r? @larsbergstrom (or anyone)
Update rust-layers to fix empty BufferRequest failures

rust-layers will now avoid sending empty buffer requests which can
cause failures when Servo tries to create empty platform surfaces.

Fixes #4060.
implement Document#createAttribute
Fixes 4037. Enable backtrace on run cmd.
auto merge of #4067 : wenderen/servo/document-create-attribute, r=Manishearth

fixes #4054
auto merge of #4074 : mrobinson/servo/empty-tiles, r=jdm

rust-layers will now avoid sending empty buffer requests which can
cause failures when Servo tries to create empty platform surfaces.

Fixes #4060.
Use atom! in place of Atom::from_slice where necessary
auto merge of #4075 : nwin/servo/fix-4037, r=Ms2ger

Fixes #4037
Break out of loop if can't send data

Fixes #4046
Make sure directories aren't getting tested
auto merge of #4072 : frewsxcv/servo/test-files, r=jdm

Fixes #3910
Adds --release flag to ./mach build-cef

Requested by kmc in IRC.

```
11:36 < kmc> while you're mach-ing about, can you modify build-cef to
accept --release like build does?
```
auto merge of #4077 : mttr/servo/mach_build_cef_release, r=kmcallister

Requested by kmc in IRC.

```
11:36 < kmc> while you're mach-ing about, can you modify build-cef to
accept --release like build does?
```
Update mach to latest changes from mozilla-central

Updates the way mach mixes unrecognized arguments and predefined
arguments (see [mozilla bug
1076649](https://bugzilla.mozilla.org/show_bug.cgi?id=1076649) for
details on this change).
Remove allow_all_args from mach commands
auto merge of #4064 : trevorriles/servo/isintervalenum, r=jdm

Created an `IsInterval` enum to improve readability and remove the need for `true // is_interval`

I'm still fairly new to rust. I briefly looked for a way to implement boolean comparisons of the enum but didn't figure out a way. 

Also I'm not attached to any of the names. Let me know what I can fix :)
auto merge of #4068 : Manishearth/servo/atomify, r=jdm