[Android] Integrate external extensions in make_apk.py

The API for external extensions are basically ready so this is to
enable the packaging tool to package external extensions into web
app APKs.

To add one extension to be packged, developers need to do below steps:
1. Create a directory named 'foobar' and add 3 files called 'foobar.jar'
'foobar.js' and 'foobar.json' into the directory.
2. Package it when running make_apk.py:
   python make_apk.py --extensions="/path/to/foobar"

BUG=#558
Merge pull request #798 from yongsheng/extension_maker

[Android] Integrate external extensions in make_apk.py
[Android] make_apk.py should exit before it calls others when failed.

Because the current process only get the output of subprocess, but can't
get the exception from the subprocess, so the parent process can't check
whether subprocess failed, and continue to run the following script.

This patch forces the parent process to read the returncode of subprocess
before continue execution, and direct exit when the returncode doesn't
equal to 0.

BUG=https://github.com/crosswalk-project/crosswalk/issues/789
Merge pull request #802 from junmin-zhu/failedprocess

[Android] make_apk.py should exit before it calls others when failing.
[Android] Add target to pack xwalk core library

And archive the tarball of xwalk core library.
The tarball will be used by cordova xwalk container.
Merge pull request #813 from wang16/cordova_lib

[Android] Add target to pack xwalk core library
Bump version to 1.29.10.0
[Extensions] Use a IO message loop for extensions running in a thread

Some extensions (like the RawSocket) will need this kind of main loop
for watching file descriptor events. The Chromium Socket implementation
asserts when used in a non-IO message loop.
Merge pull request #815 from tmpsantos/io_loop2

[Extensions] Use a IO message loop for extensions running in a thread
[Extensions] Decouple the FunctionHandler from the Internal Extension Context

This is the first step for removing the InternalExtension class. The idea here
is to delegate the wrapping of callback ids to the FunctionHandler and make
it optional using composition.
[Extensions] Convert the parameters of the function handlers into a struct

The previous syntax was too verbose and now with the struct, adding
a new parameter won't cause a mass rename.
[Tizen] Sensor support

SensorProvider class is designed to abstract sensor framework and
provide all sensor related notification for xwalk (currently support
rotation, orientation, will support motion, compass, geolocation
and gyroscope in future). TizenPlatformSensor is the platform
depended part for Tizen mobile system. It is designed to not depend
Tizen in build time.
[Extensions] Remove the InternalExtension class

All the functionality was moved tho the ExtensionFunctionHandler and
can be optionally used via composition.
Bump version to 1.29.11.0
Merge pull request #520 from tmpsantos/internal_extensions_refactoring

Internal Extensions Refactoring
Bump version to 1.29.12.0
[Extensions] Add XWalkExtensionFunctionHandler unit tests
[Tools] Adjust increment-version.py's style to Google's.

In other words, replace unix_style_functions() with CamelCased() ones.
Merge pull request #818 from rakuco/fix-increment-version-style

[Tools] Adjust increment-version.py's style to Google's.
Bump version to 1.29.13.0