[Android] Adjust the parameters for extension's two methods for reflection.

The onMessage and onSyncMessage are changed due to the support for multiple
instances for extension mechanism. However, the Java extension mechanism
doesn't change its parameters when looking up the methods for external
extensions. The unit test for external extensions will be added soon.

BUG=
[Extension] Fix build failure on Windows

Use '\' for the product_dir on Windows in external_extension_sample.gyp.
Otherwise, the build system can't handle the path well in some cases,
e.g. creating or deleting them.
It fails the windows build when it starts from zero.
Merge pull request #969 from wang16/fix_windows

[Extension] Fix build failure on Windows
Merge pull request #978 from yongsheng/multiinstance

[Android] Adjust the parameters for extension's two methods for reflecti...
[Android] Add the interface of loadAssetFile and onTitleChanged.

Add the interfaces in embedded and shared mode.
loadAssetFile: It is needed when we put the test files(eg. html) under
the test assets.
onTitleChanged: Implement a callback function in the test client,
transfer it to XWalkCoreProvider, then set it to the XWalkWebChromeClient,
In the XWalkWebChromeClient,'s callback, invoke the callback functions
which we defined, notify the test client about the title changed.
Move most of the util codes to a utility folder for reuse.
[Android] Add the dependency about test apk.

On the buildbot, we need to generate the
XWalkRuntimeClientEmbeddedTest.apk and XWalkRuntimeClientTest.apk
before the instrumentation test.
Merge pull request #970 from wuhengzhi/runtime_client

[Android] Add the interface of loadAssetFile and onTitleChanged.
Merge pull request #985 from wuhengzhi/xwalk

[Android] Add the dependency about test apk.
[Windows] Enable aura on Windows

The origin MACRO protection for XWalkViewsDelegate
is "#if !defined(OS_WIN) && defined(USE_AURA)", which
is not appropriate on Windows after Windows build also
switches to use aura.

Change the condition to "#if defined(USE_AURA)" and
implement the missing abstract function on Windows.
[Android] Disabled two test cases about ExtensionBroadcast and ExtensionEchoMultiFrames.

Due to these two test cases failed on buildbot, disabled them temporally.
They will be enabled later.
Merge pull request #989 from wuhengzhi/runtime_client

[Android] Disabled two test cases about ExtensionBroadcast and Extension...
Bump version to 2.31.25.0
Merge pull request #987 from wang16/windows_aura

[Windows] Enable aura on Windows
Bump version to 2.31.26.0
[Android] Update packaging tool and parsing tool to support extended manifest fields.

1  There are extended fields are added into the updated manifest specification.
2  In the packaging tool and parsing tool, adding the parsing and packaging
   process of handling the following fields: launch_path, application version,
   application descrition and permissions(geolocation). For the field of
   description, the /path/to/res/values/strings.xml and the correspoding field
   in /path/to/AndroidManifest.xml are associatively processed.
3  Update the correspoding test cases.