Sending exit message to devtools to exit.

Accepted and closed incoming streams

Added header to for constant use.

Removed extra spaces.

Corrected spacing to conform to coding standards.

Corrected spacing to conform to coding standards.

Corrected spacing to conform with coding standards.

Moving new import next to old import for devtools_traits as specified in comment.

Removed method definition to include as inline code and changed to iter_mut.

Using loops to exit devtools on server exit message and disconnected message to simply break as suggested in the comment.

Removing TODO comment for completed functionality.

Moved the operation for exit of devtools on servo closing outside the match loop.

Removing trailing ';' and adding new line before connection closing loop.
Use the correct Rust path in Android packaging
 Update README for Homebrew.

glfw3 is in the `homebrew/homebrew-versions` repository.
Spacing changes corrected.
auto merge of #3796 : shanil-puri/servo/ServoExitDevtools, r=jdm
Fix freetype build, pick up https://github.com/servo/libfreetype2/pull/3
auto merge of #3991 : Hoverbear/servo/patch-1, r=jdm

glfw3 is in the `homebrew/versions` keg.

```bash
➜  ~  brew install glfw3
Error: No available formula for glfw3
Searching formulae...
Searching taps...
homebrew/versions/glfw3
```

Simplest fix:

```bash
﻿➜  ~  brew install homebrew/versions/glfw3
Cloning into '/usr/local/Library/Taps/homebrew/homebrew-versions'...
remote: Counting objects: 2495, done.
remote: Total 2495 (delta 0), reused 0 (delta 0)
Receiving objects: 100% (2495/2495), 820.05 KiB | 462.00 KiB/s, done.
Resolving deltas: 100% (1433/1433), done.
Checking connectivity... done.
Tapped 161 formulae
==> Installing glfw3 from homebrew/homebrew-versions
==> Downloading https://downloads.sourceforge.net/project/glfw/glfw/3.0.4/glfw-3.0.4.tar.bz2
Already downloaded: /Library/Caches/Homebrew/glfw3-3.0.4.tar.bz2
==> Patching
patching file CMakeLists.txt
Hunk #1 succeeded at 370 with fuzz 1 (offset 13 lines).
==> cmake -DCMAKE_INSTALL_PREFIX=/usr/local/Cellar/glfw3/3.0.4 -DCMAKE_BUILD_TYPE=None -DCMAKE_FIND_FRAMEWORK=LAST -DCMAKE_VERBOSE_MAKEFILE=ON -Wno-dev -DGLFW_USE_CHDIR=TRUE -DGLFW_USE_MENUBAR=TRUE -DBUIL
==> make install
🍺  /usr/local/Cellar/glfw3/3.0.4: 11 files, 220K, built in 9 seconds
```

Users who have `homebrew/versions` already tapped won't notice this, since after tapping `homebrew/versions` keg shouldn't notice, since after tapping, the library is available using just ` brew install glfw3`.

```bash
➜  ~  brew tap
homebrew/versions
➜  ~  brew install glfw3
==> Installing glfw3 from homebrew/homebrew-versions
==> Downloading https://downloads.sourceforge.net/project/glfw/glfw/3.0.4/glfw-3.0.4.tar.bz2
Already downloaded: /Library/Caches/Homebrew/glfw3-3.0.4.tar.bz2
==> Patching
patching file CMakeLists.txt
Hunk #1 succeeded at 370 with fuzz 1 (offset 13 lines).
==> cmake -DCMAKE_INSTALL_PREFIX=/usr/local/Cellar/glfw3/3.0.4 -DCMAKE_BUILD_TYPE=None -DCMAKE_FIND_FRAMEWORK=LAST -DCMAKE_VERBOSE_MAKEFILE=ON -Wno-dev -DGLFW_USE_CHDIR=TRUE -DGLFW_USE_MENUBAR=TRUE -DBUIL
==> make install
🍺  /usr/local/Cellar/glfw3/3.0.4: 11 files, 220K, built in 9 seconds
```
Reformat sniffer_task.rs.
auto merge of #4017 : Ms2ger/servo/sniffertask, r=jdm
auto merge of #4016 : SimonSapin/servo/fix-freetype-build, r=Manishearth

Pick up https://github.com/servo/libfreetype2/pull/3

r? @Manishearth
auto merge of #3987 : mbrubeck/servo/rust-root, r=larsbergstrom

r? @larsbergstrom
Various cleanup in constellation.rs.
auto merge of #4019 : Ms2ger/servo/constellation, r=mbrubeck
Initial attempt at rerolling patch from PR-2610
Change previous statics into consts.
Amend names accordingly as they should be uppercase.
Add new options to FlowFlags, and expand it from u8 to u16 to accomodate.
Remove trailing whitespace
fixup! Change previous statics into consts. Amend names accordingly as they should be uppercase. Add new options to FlowFlags, and expand it from u8 to u16 to accomodate.
fixup! Initial attempt at rerolling patch from PR-2610
Merge two use into one
fixup! Initial attempt at rerolling patch from PR-2610