[Android] Fix XWalk crash issue when exiting if remote debugging is enabled.

The root cause is that DevToolsHttpHandlerImpl::Stop has been called before
DevToolsClientHostImpl::InspectedContentsClosing. In that case, the thread
is released and message loop is set to null, so XWalk crashes.

The fix is to change the teardown sequence to destory view first, then shutdown
remote debugging server.

BUG=https://crosswalk-project.org/jira/browse/XWALK-312
Merge pull request #1115 from huningxin/remote-debugger-crash-fix

[Android] Fix XWalk crash issue when exiting if remote debugging is enab...
[Android] Add version number tracking for packing tool.

The version number of packing tool is the same as that of XWalk.
With the version, it would be easier to track bugs for packing tool.
Usage: python make_apk.py -v

BUG=https://crosswalk-project.org/jira/browse/XWALK-163
Merge pull request #1087 from junmin-zhu/version

[Android] Add version number tracking for packing tool.
WIP