[Extensions] Check for conflicting entry points in the ModuleSystem

As we may have extensions coming from various processes, think that internal
extensions are run in the Browser Process and external extensions are run in
the Extension Process, the only point when we have all information of all the
extensions that would be run for a context is the module system.

So, if conflicting entry points are found, we log this as an warning and do
not register the extension.
Enable overlay scrollbars for all platforms

We need overlay scrollbars for Tizen and any platform supporting
viewport changes (@viewport or meta tag). Chromium is going in the
same direction.

To get the right size, offset from viewport edge and fade out,
additional changes are needed to Chromium.
Merge pull request #1081 from kenchris/overlaysb

Enable overlay scrollbars for all platforms
[Extensions] Disable the Extension Framework entirely for --install and --uninstall

As mentioned in https://github.com/crosswalk-project/crosswalk/issues/839,
we shouldn't be bootstrapping the entire BrowserProcess workflow when using
xwalk --install or xwalk --uninstall.

This patch disables the ExtensionService creation, the Extensions
loading and the Extensions registering as a workaround for the
crash mentioned in https://crosswalk-project.org/jira/browse/XWALK-31 .
Merge pull request #1040 from vcgomes/module-system-check-entry-points

[Extensions] Check for conflicting entry points in the ModuleSystem
Merge pull request #1083 from jeez/fix-segfault-crosswalk

[Extensions] Disable the Extension Framework entirely for --install and --uninstall
Build fix, kEnableOverlayScrollbars is not exported via CONTENTS_EXPORT

Define kEnableOverlayScrollbars ourselves.
Merge pull request #1084 from kenchris/overlaysb

Build fix, kEnableOverlayScrollbars is not exported via CONTENTS_EXPORT
Bump version to 3.31.32.0
Merge pull request #1067 from tmpsantos/raw_socket_common

[SysApps] Introduce SysApps foundations
[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.
[SysApps] Make it possible to create a TCPSocket from a connected socket

The TCPServerSocket will need to create a TCPSocket from incoming connections.
This patch makes it possible to create an object in the native side first and
handle the identifier to the JavaScript context.
[SysApps] Add TCPServerSocket implementation

Added an incomplete but functional implementation of the
Raw Sockets TCPServerSocket interface.
[SysApps] Add browser tests for the Raw Socket JavaScript API

Tests if the objects are leaky and if the basic functionality like
send and receive data works. These tests are not API conformance tests.