[Android] Put app resource in sub directory of assets

Before this all app resources are put in assets, which may cause
confliction with other resources(of runtime, extensions etc).
So we define a sub directory "www" to put the app resources
instead.

BUG=https://crosswalk-project.org/jira/browse/XWALK-174
[Android] Fix that instrumentation test is not using ShellActivity

The correct usage of instrumentation test is to direct operate
the Activity in target package instead of creating one.

Change the test util base Class to get XWalkRuntimeClient from
XWalkRuntimeActivityBase.

TODO(hengzhi): Fix the same issue with CoreShellTest and RuntimeShellTest
[Android] Add app URI scheme support

1 App URI scheme is part of sysapps API, http://app-uri.sysapps.org
2 On Android the local resources are located in assets, which could
be accessed by file:///android_asset/ scheme. So we bridge the app
URI to file URI.
3 Add the HTTP response support(200, 400, 403, 404, 501).

BUG=https://crosswalk-project.org/jira/browse/XWALK-174
[Android] Fix the app local path parser issue in manifest parser.

  The app local path field is not parsed correctly. This fix it to
resolve this issue by adding the judgement from app->launch->local_path.

BUG=https://crosswalk-project.org/jira/browse/XWALK-695
Merge pull request #1353 from ShDavidliu/update_parser

[Android] Fix the app local path parser issue in manifest parser.
Merge pull request #1323 from wang16/test_refine

[Android] Fix that instrumentation test is not using ShellActivity
﻿[Android] Enable the io thread client in xwalk content.

  The io thread client is implemented while not enabled in xwalk content,
this fix is to enable the io thread client in xwalk content and adding the
related handler into the xwalk content native layer and java layer.

BUG=https://crosswalk-project.org/jira/browse/XWALK-653
[Runtime] Register system events information into database during installation.

As is mentioned in https://crosswalk-project.org/jira/browse/XWALK-519,
this PR registers system events at application install time. In detail,
after installation of application pacakge is completed, the main
document will be executed to register the events into system database.
Merge pull request #1255 from xingnan/app-shcheme

App scheme
Merge pull request #1309 from ShDavidliu/io_thread_client

[Android] Enable the io thread client in xwalk content.
[SysApps][Android] W3C SysApps Messaging API

The implementation is based on 29 November 2013 editor's draft version
http://www.w3.org/2012/sysapps/messaging/

Completed features list:

Send/receive SMS messages.
Find/list SMS messages
Find/list SMS conversations
Delete SMS messages
Delete SMS conversations
Mark SMS message read status
Mark SMS conversation read status
Feature: https://crosswalk-project.org/jira/browse/XWALK-53

MMS Features is holded. Waiting for Android official Mms API ready.
Merge pull request #1339 from shawngao5/shawn_dev_sms

[SysApps][Android] W3C SysApps Messaging API
Bump Crosswalk's major version to 4.

BUG=https://crosswalk-project.org/jira/browse/XWALK-712
Merge pull request #1362 from rakuco/crosswalk-v4-bump

Bump Crosswalk's major version to 4.
[SysApps] Introduce the SysAppsManager

This class will be the single entry point for registering all
the SysApps extensions. It should be the only class of the "sysapps"
namespace exposed to other subsystems.

In the future it will also manage the lifecycle of data providers (platform
abstractions for extensions like DeviceCapabilities).
[SysApps] Add a "sysapps" master flag

A single flag to disable all the SysApps APIs.
[SysApps] Add unit tests for the SysAppsManager
[Extensions] Fix runtime symbol missing for xesh

Fixes runtime error when building with component=shared_library.

symbol lookup error: libglue_child.so: undefined symbol: HeapProfilerStart
Merge pull request #1364 from tmpsantos/xesh_missing_symbol

[Extensions] Fix runtime symbol missing for xesh
Merge pull request #1235 from shaochangbin/register-system-events

[Runtime] Register system events information into database during installation.