[Android] Support embedded mode in packaging tool.

Some developers want to package web app with independent
xwalk's runtime library, and don't care the size of it
too much.

Pacakaging tool would copy all the xwalk's runtime library
into target application package, which includes the
.so, .jar, .apk file etc. By default, packaging tool
uses shared mode for web application.

Sample Usage:
python make_apk.py --name=Intel --package=org.xwalk.example
--app-url=http://www.intel.com --mode=embedded

BUG=https://github.com/crosswalk-project/crosswalk/issues/765
[Android] Disable CORS for file:// schemes.

Cross-Origin request breaks the web security policy, only same-origin
request should be allowed for file:// schemes, so universal access
from file URLs should be closed.

BUG=https://github.com/crosswalk-project/crosswalk/issues/790
Bump version to 2.31.17.0
Fix the issue getUserMedia can't work if rebasing to Chromium 31

Crosswalk debug mode crashed when it accessed getUserMedia API, and
release mode also can't work.

The root cause was listed as followed:
1. Chromium upstream improved related code, now EnsureMonitorCaptureDevices
   is just a wrapper, it runs in UI thread, and the real major code is
   still running in IO thread.
   Please see: https://codereview.chromium.org/17508005/
2. It is an error from rebasing, GetMediaObserver callback was changed
   to be NULL.
Merge pull request #878 from yinli/getUserMedia_yinli

Fix issue getUserMedia can't work when based chromium rebased to 31
Merge pull request #791 from gaochun/permission_control

[Android] Disable Cross-Origin request by default.
Merge pull request #809 from junmin-zhu/embed

[Android] Support embedded mode in packaging tool.
Enable Aura build on all platforms except Android

Enable Aura build on all platforms except Android.
Merge pull request #897 from pozdnyakov/Enable_Aura_except_Android

Enable Aura build on all platforms except Android
[Extensions] Add SetExtraEntryPoints to Extension C API

This will allow for Extension to inform if they have other entry
points (apart from the implicit extension_name), that should cause
the extension to be loaded.

For example, the "calendar" extension may export some constants in the
CalendarAppointment object, and we want the calendar extension to be
loaded when any of these "main" objects are accessed.