[Android] Fix the issue of '--app-root' and '--app-local-path'

For make_apk.py, if the option '--app-root' is required, it's
necessary to include the option '--app-local-path' as well.
Besides, split the test cases in 'testEntry' into 2 categories:
one is for testing correct cases and another is for failures.
[Android] Handle exceptions during the cross package invoking

All exceptions was causing library-not-found dialog to show before.
It was not appropriate.

Now the implementation is that the exception are catagorized into:
1. Runtime library not installed;
2. Runtime library not up-to-date and it's critical;
3. Runtime library not up-to-date but bearable;
4. Error happening before version matching across package;
5. Error happening after version matching across package.
For the first four cases, a dialog will be shown to navigate user to
download/upgrade runtimelib with proper message.
For the last case, since the version is already matched, the exception
should be taken as a normal runtime exception and be thrown out.

BUG=https://github.com/crosswalk-project/crosswalk/issues/735
[Android] Implement mixed resources to fix resource not found

In shared mode, runtime client and library are in different packages.
It makes it easy to meet resource-not-found issue.

To fix that, class XWalkMixedResources is created to combine the two
resources into one. It will try to get resource from library first
and get from client when resource not found in library.

BUG=https://github.com/crosswalk-project/crosswalk/issues/796
Merge pull request #744 from wang16/exception_handle

[Android] Handle exceptions during the cross package invoking
[Android] Remove unused application customization

It's not necessary to override android.app.Application but
do nothing customized.
Remove them and just use android.app.Application in their
AndroidManifest.xml.
Merge pull request #803 from wang16/mix_resources

[Android] Implement mixed resources to fix resource not found
Merge pull request #730 from wang16/remove_app

[Android] Remove unused application customization
Merge pull request #797 from yongsheng/testentry

[Android] Fix the issue of '--app-root' and '--app-local-path'