[Windows] Fix runtime is using wrong content_app target

On Windows, upstream is trying to provide alternative to split
chrome.dll into several parts. Therefore, target content_app
is now content_app_browser, content_app_child, content_app_both.
It's not relevant with xwalk, xwalk should use content_app_both
to obtain all it need for content app.
Bump version to 2.31.27.0
Merge pull request #1003 from wang16/fix_windows

[Windows] Fix runtime is using wrong content_app target
[Android] Add getDisplay() to XWalkDisplayManager

WiDi PR #965 add XWalkDisplayManager class referenced from
DisplayManager class introduced since Android 4.2 (API Level 17).

While getDisplay() is not included because WiDi does not use it.
This PR is adding that this api and implementation.
[Android] Add XWalkManifestReader.java to xwalk_core_library project.

The Java class XWalkManifestReader provides the content of app
manifest. Missing of XWalkManifestReader will lead to error of
core library project, so add it to xwalk_core_library.

This patch also fixes some coding style issues.
[Android][Extensions] Implemented W3C SysApps Device Capabilities API

The implementation is based on 17 October 2013 editor draft version.
CPU, Memory, Storage and Display are included, the Audio and Video Codecs
is not implemented yet.

SPEC=http://www.w3.org/2012/sysapps/device-capabilities/
BUG=https://crosswalk-project.org/jira/browse/XWALK-48
[Android] Destroy extension when activity is destroyed

This fix is to ensure that XWalkExtension object gets destroyed when the
Activity is destroyed (e.g. press back button).

Since each XWalkExtension object on Java side has a corresponding native
extension object, we need to make sure the native extension object is
also destroyed. Otherwise, the leaked native object will cause unpredictable
program behavior.

BUG=https://github.com/crosswalk-project/crosswalk/issues/1023
Merge pull request #1042 from gaochun/cordova_xwalk

[Android] Add XWalkManifestReader.java to xwalk_core_library project.
Merge pull request #961 from halton/device_capabilities

[Android][Extensions] Implemented W3C SysApps Device Capabilities API
Merge pull request #1030 from hmin/destroy-extension

[Android] Destroy extension when activity is destroyed
[Android] Disable the unit test for DeviceCapabilities.

It's failed in both shared and embedded modes. Need to fix them.
Create one issue to track it:
https://crosswalk-project.org/jira/browse/XWALK-102
Merge pull request #1045 from yongsheng/master

[Android] Disable the unit test for DeviceCapabilities.
[Extensions] Add support for persistent callback listener

This is going to be the base of the EventTarget implementation. It is
important to remove the listener at some point otherwise the object will
leak.
[Extensions] Add browsertests for the persistent callback listener

The test implements a heartbeat which works in a similar way of an EventTarget.
The callback is set only one and gets called multiple times.
[SysApps] Add the convenience classes and prototypes

These C++ classes and JavaScript prototypes are helpers for the common
places that appear all around the SysApps APIs specifications.

The main features are:

- Helpers for creating objects managed by the extension.
- Easy way of declaring API methods.
- EventTarget implementation, and thus, helpers for dealing with
  events.

For more information, check the documentation on the code.
[SysApps] Make the common API availiable as a module

Make it available to be accessed via requireModule(). It is going
to be used by the SysApps APIs like Raw Socket.
[SysApps] Add unit tests for the convinience classes
[SysApps] Add browser tests for the common JavaScript API

These tests are testing the functionality of the helper JavaScript
prototypes and objects, like the EventTarget.
[SysApps] Add Raw Sockets stub

Just the skeleton to serve as base for the interfaces implementation. No API is
currently exposed.
[SysApps] Add the TCPSocket implementation

This is the initial implementation of the W3C's Raw Sockets TCPSocket interface.
It is not complete but is fully functional. Some issues with the spec are being
worked with the standardization body, like the fact that the send() method is
technically sync (although we implement as async always returning true).

A notable missing feature is the throwing of exceptions on invalid parameters,
but the error callback is still called under these circumstances.

We also add the RawSocketObject class. This class is going to concentrate all
the shared code among the different interfaces of the Raw Socket API. Currently only
the ReadyState is shared.